This reverts commit 735c018.

We need to recurse into stripped modules to strip things like impl methods
but when doing so we must not add any items to the `retained` set.

… on the statement

…ssify ident patterns

These are caused by `DefaultImpl`s.

…eir children.

…nique, r=nrc

Give `ast::ExprKind::Paren` no-op expressions the same ids as their children.

Having `ast::ExprKind::Paren` expressions share ids with their children
 - reduces the number of unused `NodeId`s in the hir map and
 - guarantees that `tcx.map.expect_expr(ast_expr.id)` is the hir corresponding to `ast_expr`.

This fixes the bug from rust-lang#34327, which was introduced in rust-lang#33296 when I assumed the above guarantee.

r? @nrc

Treat `MultiDecorator`s as a special case of `MultiModifier`s

This deals with rust-lang#32950 by using @durka's [option 1](rust-lang#33769 (comment)).
r? @nrc

Miscellaneous macro expansion cleanup and groundwork

r? @nrc

Add regression test for rust-lang#33455

Closes rust-lang#33455.

Add new error codes and improve some explanations

r? @brson

cc @steveklabnik
cc @jonathandturner

…ons, r=eddyb

Forbid type parameters and global paths in macro invocations

Fixes rust-lang#28558.
This is a [breaking-change]. For example, the following would break:
```rust
macro_rules! m { () => { () } }
fn main() {
    m::<T>!(); // Type parameters are no longer allowed in macro invocations
    ::m!(); // Global paths are no longer allowed in macro invocations
}
```
Any breakage can be fixed by removing the type parameters or the leading `::` (respectively).

r? @eddyb

Revert "skip double negation in const eval"

This reverts commit 735c018.

fixes rust-lang#34395

The original commit was based on a mis-understanding of the overflowing literal lint.

This needs to be ported to beta.

r? @eddyb

…alexcrichton

Disable debuginfo tests for a given blacklist of LLDB versions

Anyone having trouble with most LLDB tests failing on OSX, please report your LLDB version here so I can add it to the blacklist.

Blacklisted versions so far:
* lldb-350.*

cc @rust-lang/tools
cc @tedhorst @indutny @jonathandturner (people from the original bug report)

Fixes rust-lang#32520.

…chton

rustdoc: Fix a few stripping issues

We need to recurse into stripped modules to strip things like impl methods
but when doing so we must not add any items to the `retained` set.

For example this removes [`core::num::ParseFloatError::__description`](https://doc.rust-lang.org/nightly/core/num/struct.ParseFloatError.html#method.__description) and [`impl Clone for ThreadRng`](https://doc.rust-lang.org/nightly/std/clone/trait.Clone.html).

…xcrichton

rustdoc: Fix empty Implementations section on some module pages

These are caused by `DefaultImpl`s.

For example [`core::marker`](https://doc.rust-lang.org/nightly/core/marker/#impls).

Fix non-termination on recursive module re-exports in extern crates

Fixes rust-lang#33776.
r? @nrc