Downgrade ProjectionTy's TraitRef to its substs
Addresses the second part of #42171 by removing the `TraitRef` from
`ProjectionTy`, and directly storing its `Substs`.
Closes#42171.
Use similar compression settings as before updating to use flate2
Fixes#42879
(My first PR to rust-lang yay)
This changes the compression settings back to how they were before the change to use the flate2 crate rather than the in-tree flate library. The specific changes are to use the `Fast` compression level (which should be equivialent to what was used before), and use a raw deflate stream rather than wrapping the stream in a zlib wrapper. The [zlib](https://tools.ietf.org/html/rfc1950) wrapper adds an extra 2 bytes of header data, and 4 bytes for a checksum at the end. The change to use a faster compression level did give some compile speedups in the past (see #37298). Having to calculate a checksum also added a small overhead, which didn't exist before the change to flate2.
r? @alexcrichton
Only match a fragment specifier the if it starts with certain tokens.
When trying to match a fragment specifier, we first predict whether the current token can be matched at all. If it cannot be matched, don't bother to push the Earley item to `bb_eis`. This can fix a lot of issues which otherwise requires full backtracking (#42838).
In this PR the prediction treatment is not done for `:item`, `:stmt` and `:tt`, but it could be expanded in the future.
Fixes#24189.
Fixes#26444.
Fixes#27832.
Fixes#34030.
Fixes#35650.
Fixes#39964.
Fixes the 4th comment in #40569.
Fixes the issue blocking #40984.
Test src/doc once more
This was accidentally broken in https://github.com/rust-lang/rust/pull/42437 since we filtered too early to recurse into sub-directories.
In theory, @bors p=10
r? @alexcrichton
Fix feature gate for `#[link_args(..)]` attribute
Fix feature gate for `#[link_args(..)]` attribute so that it will fire regardless of context of attribute.
See also #29596 and #43106
Store all generic arguments for method calls in AST/HIR
The first part of https://github.com/rust-lang/rust/pull/42492.
Landed separately to start the process of merging libsyntax changes breaking rustfmt, which is not easy these days.
Fix stage 2 builds with a custom libdir.
When copying libstd for the stage 2 compiler, the builder ignores the
configured libdir/libdir_relative configuration parameters. This causes
the compiler to fail to find libstd, which cause any tools built with the
stage 2 compiler to fail.
To fix this, make the copy steps of rustbuild aware of the libdir_relative
parameter when the stage >= 2. Also update the dist target to be aware of
the new location of libstd.
Implemented `TypeFoldable` for `TypeError`s.
This is quite handy in some user code, for instance to pull out type errors from an inference context when `fresh_substs_for_item` has been used before.
Remove unused code from librustc_errors
While extracting librustc_errors into a [reusable library](https://github.com/kevinmehall/codemap-diagnostic), I noticed some obsolete code that the `dead_code` warning missed because it was marked `pub` but not used elsewhere.
