Add readmes to reflection

src/libraries/System.Reflection.Context/readme.md

@@ -0,0 +1,7 @@
+# System.Reflection.Context
+Used by `System.ComponentModel` to support [`CustomReflectionContext`](https://learn.microsoft.com/dotnet/api/system.reflection.context.customreflectioncontext).
+
+## Status: [Legacy](../system.reflection/overview.md#status)
+
+## Deployment
+https://www.nuget.org/packages/System.Reflection.Context

src/libraries/System.Reflection.DispatchProxy/readme.md

@@ -0,0 +1,8 @@
+# System.Reflection.DispatchProxy
+Supports the [`DispatchProxy`](https://learn.microsoft.com/dotnet/api/system.reflection.dispatchproxy) class which is used to forward methods to another class.
+
+## Status: [Legacy](../system.reflection/overview.md#status)
+Although used for key scenarios by the community, it has remained relatively unchanged. Internally it uses [Emit](../System.Reflection.Emit/readme.md) to generate the proxies so it doesn't work on all platforms.
+
+## Deployment
+https://www.nuget.org/packages/System.Reflection.Context

src/libraries/System.Reflection.Emit.ILGeneration/readme.md

@@ -0,0 +1,8 @@
+# System.Reflection.Emit.ILGeneration
+Contains types used with [`System.Reflection.Emit`](../system.reflection.emit.readme.md).
+
+## Status: [Inactive](../system.reflection/overview.md#status)
+
+## Deployment
+Inbox  
+https://www.nuget.org/packages/System.Reflection.Emit.ILGeneration

src/libraries/System.Reflection.Emit.Lightweight/readme.md

@@ -0,0 +1,10 @@
+# System.Reflection.Emit.Lightweight
+
+## Status: [Inactive](../system.reflection/overview.md#status)
+
+## Deployment
+Inbox  
+https://www.nuget.org/packages/System.Reflection.Emit.Lightweight
+
+## See also
+[`System.Reflection.Emit`](../system.reflection.emit/readme.md)

src/libraries/System.Reflection.Emit/readme.md

@@ -0,0 +1,25 @@
+# System.Reflection.Emit
+Supports generating code dynamically and then running it in-memory. The primary class is [`AssemblyBuilder`](https://learn.microsoft.com/dotnet/api/system.reflection.emit.assemblybuilder).
+
+Not all platforms and runtimes support IL.Emit.
+
+This library is often used with [`System.Reflection.Emit.ILGeneration`](../system.reflection.emit.ilgeneration/readme.md).
+
+## Status: [Inactive](../system.reflection/overview.md#status)
+The APIs and functionality are mature, but do get extended occasionally.
+
+## Deployment
+Inbox  
+https://www.nuget.org/packages/System.Reflection.Emit
+
+### Source
+Runtime code for CoreClr:
+https://github.com/dotnet/runtime/tree/main/src/coreclr/System.Private.CoreLib/src/System/Reflection/Emit  
+for Mono:  
+https://github.com/dotnet/runtime/tree/main/src/mono/System.Private.CoreLib/src/System/Reflection/Emit  
+Shared code between CoreClr and Mono:
+https://github.com/dotnet/runtime/tree/main/src/libraries/System.Private.CoreLib/src/System/Reflection/Emit
+
+### See also
+
+[`System.Reflection.Emit.Lightweight`](..\system.reflection.emit.lightweight.readme.md)

src/libraries/System.Reflection.Extensions/readme.md

@@ -0,0 +1,8 @@
+# System.Reflection.Extensions
+This supports static extension methods for common reflection types. For similar extensions, see also [`System.Reflection.TypeExtensions`](../System.Reflection.TypeExtensions/readme.md). This assembly contains no implementations; the declared types are forwarded to the runtime.
+
+## Status: [Inactive](../system.reflection/overview.md#status)
+
+## Deployment
+Inbox
+https://www.nuget.org/packages/System.Reflection.Extensions

src/libraries/System.Reflection.Metadata/readme.md

@@ -0,0 +1,11 @@
+# System.Reflection.Metadata
+This provides a low-level API for inspecting raw assembly contents according to ECMA-335. Assemblies and types are not loaded into the current runtime context.
+
+The primary classes are [MetadataReader](https://learn.microsoft.com/dotnet/api/system.reflection.metadata.metadatareader) and [MetadataBuilder](https://learn.microsoft.com/en-us/dotnet/api/system.reflection.metadata.ecma335.metadatabuilder?view=net-6.0).
+
+## Status: [Inactive](../system.reflection/overview.md#status)
+The APIs and functionality are mature, but do get extended occasionally.
+
+## Assemblies
+Inbox
+https://www.nuget.org/packages/System.Reflection.Metadata

src/libraries/System.Reflection.MetadataLoadContext/readme.md

@@ -0,0 +1,14 @@
+# System.Reflection.MetadataLoadContext
+This provides a high-level API for inspecting raw assembly contents according to ECMA-335. Types from an assembly are loaded into the provided [`MetadataLoadContext`](https://learn.microsoft.com/dotnet/api/system.reflection.metadataloadcontext) instance which provide for introspection purposes by returning `System.Type`, `System.MemberInfo`, etc. However, these reflection types do not support invocation.
+
+This library takes a dependency on `System.Reflection.Metadata` for reading the assembly.
+
+## Status: [Inactive](../system.reflection/overview.md#status)
+The APIs and functionality are mature, but do get extended occasionally.
+
+## Source
+https://github.com/dotnet/runtime/tree/main/src/libraries/System.Reflection.Metadata
+
+## Deployment
+Inbox  
+https://www.nuget.org/packages/System.Reflection.MetadataLoadContext (contains full code for OOB scenarios).

src/libraries/System.Reflection.Primitives/readme.md

@@ -0,0 +1,8 @@
+# System.Reflection.Primitives
+Contains reflection types such as [TypeAttributes](https://learn.microsoft.com/dotnet/api/system.reflection.typeattributes). Some of these types are forwarded to the runtime. In the future, the non-forwarded types may be lifted to the runtime and then type forwards added.
+
+## Status: [Legacy](..\system.reflection\overview.md#status)
+
+## Deployment
+Inbox
+https://www.nuget.org/packages/System.Reflection.Extensions (to redirect to the appropriate runtime).

src/libraries/System.Reflection.TypeExtensions/readme.md

@@ -0,0 +1,8 @@
+# System.Reflection.TypeExtensions
+This supports static extension methods for common reflection types. For similar extensions, see also `System.Reflection.Extensions`.
+
+## Status: [Legacy](../system.reflection/overview.md#status)
+
+## Deployment
+Inbox
+https://www.nuget.org/packages/System.Reflection.TypeExtensions

src/libraries/System.Reflection/overview.md

@@ -0,0 +1,37 @@
+# Summary
+
+Reflection is used for late-bound introspection, invocation and IL code generation. It contains:
+- **Runtime introspection and invocation** through [System.Reflection](readme.md). This is what most consider to be "reflection" and supports inspecting assemblies and types that are loaded into the currently executing "runtime context". This introspection is exposed by various reflection types including [`Assembly`](https://learn.microsoft.com/dotnet/api/system.reflection.assembly), [`Type`](https://learn.microsoft.com/dotnet/api/system.type), [`ConstructorInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.constructorinfo), [`MethodInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.methodinfo) and [`FieldInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.fieldinfo). Also supported is the ability to invoke members in a late-bound manner such as through [`MethodBase.Invoke`](https://learn.microsoft.com/dotnet/api/system.reflection.methodbase.invoke).
+- **Static introspection** through [System.Reflection.MetadataLoadContext](../System.Reflection.MetadataLoadContext\readme.md). This exposes the same reflection types as runtime introspection, but they are loaded into a "metadata context" where the types returned for introspection do not support invocation, and they are different instances from the types returned from runtime introspection. Because of this, this allows any assembly to be read, even if it's for a different platform provided that all assembly references are accounted for.  
+- **Runtime generation of IL for invocation** through [System.Reflection.Emit](../System.Reflection.Emit\readme.md). This is used to generate types dynamically which are commonly used to generate proxies and other dynamic classes that may not be known ahead-of-time (in which case C# generation could be used, for example). It is also used to invoke members more efficiently than the [`standard runtime invoke mechanism`](https://learn.microsoft.com/dotnet/api/system.reflection.methodbase.invoke). However,  due to recent work in 7.0 (which is to be extended in 8.0), this IL generation is now done automatically so the need to manually generate IL for performance is becoming less useful.
+- **Low-level reading and writing of assemblies**  through [System.Reflection.Metadata](../System.Reflection.Metadata\readme.md). This is used for tooling and compiler-like scenarios.
+- Other reflection libraries that extend the functionality above or serve as a container assembly to support NetStandard or attribute types emitted by compilers:
+  - [System.Reflection.Context](../System.Reflection.Context/readme.md)
+  - [System.Reflection.DispatchProxy](../System.Reflection.DispatchProxy/readme.md)
+  - [System.Reflection.Extensions](../System.Reflection.Extensions/readme.md)
+  - [System.Reflection.Primitives](../System.Reflection.Primitives/readme.md)
+  - [System.Reflection.TypeExtensions](../System.Reflection.TypeExtensions/readme.md)
+
+## <a name="status"></a>Status descriptions
+Each library has its own `readme.md` that contains a description plus  a current status of:
+- **Legacy**  
+Not under development; maintained for compatibility.  
+PRs are unlikely to be accepted.  
+Issues are likely to be closed without fix.
+- **Inactive**  
+Under minimal development; quality is maintained.  
+PRs for both features and fixes will be considered.  
+Issues will be considered for fix or addition to the backlog.
+- **Active**  
+Under active development by the team.
+PRs for both features and fixes will be considered and championed.  
+Issues will be considered for fix or addition to the backlog.
+
+## Futures
+The [8.0 roadmap](https://github.com/dotnet/runtime/issues/75358) covers planned work for this release.
+
+In general, active reflection investments include:
+- Keeping up with new language and runtime features, including byref-like types and AOT environments.
+- Larger, missing features requested by the community, including an `AssemblyBuilder.Save()` mechanism to persist generated IL to an assembly.
+- Performance improvements, such as automatically generating IL for invocation cases.
+- Bug fixes and smaller features.

src/libraries/System.Reflection/readme.md

@@ -0,0 +1,17 @@
+# System.Reflection
+Includes commom types such as [`AssemblyName`](https://learn.microsoft.com/dotnet/api/system.reflection.assemblyname) and [`MethodInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.methodinfo).
+
+## Status: [Active](../system.reflection/overview.md#status)
+Although these common types are mature, the code base continues to evolve for better performance and to keep up with language and runtime enhancements such as byref-like types.
+
+## Source
+Runtime code for CoreClr:
+ https://github.com/dotnet/runtime/tree/main/src/coreclr/System.Private.CoreLib/src/System/Reflection  
+for Mono:  
+https://github.com/dotnet/runtime/tree/main/src/mono/System.Private.CoreLib/src/System/Reflection
+
+Shared code between CoreClr and Mono:
+https://github.com/dotnet/runtime/tree/main/src/libraries/System.Private.CoreLib/src/System/Reflection
+
+## Deployment
+Inbox