Create FreeBSD build-target for corefx and add FreeBSD platform detec…

…tion.

This partially adresses
https://github.com/dotnet/corefx/issues/1626

dir.props

@@ -137,6 +137,7 @@
     <OSGroup Condition="'$(OSGroup)'=='' and $(Configuration.StartsWith('Windows'))">Windows_NT</OSGroup>
     <OSGroup Condition="'$(OSGroup)'=='' and $(Configuration.StartsWith('Linux'))">Linux</OSGroup>
     <OSGroup Condition="'$(OSGroup)'=='' and $(Configuration.StartsWith('OSX'))">OSX</OSGroup>
+    <OSGroup Condition="'$(OSGroup)'=='' and $(Configuration.StartsWith('FreeBSD'))">FreeBSD</OSGroup>
     <OSGroup Condition="'$(OSGroup)'==''">Windows_NT</OSGroup>
   </PropertyGroup>
 
@@ -189,8 +190,9 @@
     <TargetsWindows Condition="'$(OSGroup)' == 'Windows_NT'">true</TargetsWindows>
     <TargetsLinux Condition="'$(OSGroup)' == 'Linux'">true</TargetsLinux>
     <TargetsOSX Condition="'$(OSGroup)' == 'OSX'">true</TargetsOSX>
+    <TargetsFreeBSD Condition="'$(OSGroup)' == 'FreeBSD'">true</TargetsFreeBSD>
 
-    <TargetsUnix Condition="'$(TargetsLinux)' == 'true' or '$(TargetsOSX)' == 'true'">true</TargetsUnix>
+    <TargetsUnix Condition="'$(TargetsLinux)' == 'true' or '$(TargetsOSX)' == 'true' or '$(TargetsFreeBSD)' == 'true'">true</TargetsUnix>
   </PropertyGroup>
 
   <PropertyGroup>

src/System.Runtime.Environment/src/RuntimeInformation.FreeBSD.cs

@@ -0,0 +1,15 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace System.Runtime.InteropServices
+{
+    public static class RuntimeInformation
+    {
+        private static readonly OSName freebsd = new OSName("FREEBSD");
+
+        public static bool IsOperatingSystem(OSName osName)
+        {
+            return freebsd == osName;
+        }
+    }
+}

src/System.Runtime.Environment/src/System.Runtime.Environment.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
   <PropertyGroup>
@@ -17,6 +17,8 @@
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'OSX_Release|AnyCPU' " />
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Windows_Debug|AnyCPU' " />
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Windows_Release|AnyCPU' " />
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'FreeBSD_Debug|AnyCPU' " />
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'FreeBSD_Release|AnyCPU' " />
   <ItemGroup Condition=" '$(TargetsWindows)' == 'true' ">
     <Compile Include="RuntimeInformation.Windows.cs" />
   </ItemGroup>
@@ -26,11 +28,14 @@
   <ItemGroup Condition=" '$(TargetsOSX)' == 'true' ">
     <Compile Include="RuntimeInformation.OSX.cs" />
   </ItemGroup>
+  <ItemGroup Condition=" '$(TargetsFreeBSD)' == 'true' ">
+    <Compile Include="RuntimeInformation.FreeBSD.cs" />
+  </ItemGroup>
   <ItemGroup>
     <None Include="project.json" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="OSName.cs" />
   </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
-</Project>
+</Project>