Peephole optimize `x == false` and `x != true`
This adds peephole optimizations to make `x == false`, `false == x`, `x != true`, and `true != x` get optimized to `!x` in the `instcombine` MIR pass. That pass currently handles `x == true` -> `x` already.
Include macro name in 'local ambiguity' error
Currently, we only point at the span of the macro argument. When the
macro call is itself generated by another macro, this can make it
difficult or impossible to determine which macro is responsible for
producing the error.
Enable rustdoc to document safe wasm intrinsics
This commit fixes an issue not found during #84988 where rustdoc is used
to document cross-platform intrinsics but it was requiring that
functions which use `#[target_feature]` are `unsafe` erroneously, even
if they're WebAssembly specific. Rustdoc today, for example, already has
a special case where it enables annotations like
`#[target_feature(enable = "simd128")]` on platforms other than
WebAssembly. The purpose of this commit is to relax the "require all
`#[target_feature]` functions are `unsafe`" requirement for all targets
whenever rustdoc is running, enabling all targets to fully document
other targets, such as WebAssembly, where intrinsics functions aren't
always `unsafe`.
Comment out unused error codes and add description for E0316
I have added an extended description of `E0316` and commented out a bunch of unused error codes to make clear the fact that they are no longer in use. You can check for yourself with
```shell
for ec in \
E0314 E0315 E0473 E0474 E0475 E0479 E0480 E0481 \
E0483 E0484 E0485 E0486 E0487 E0488 E0489
do
if [ ! -z "`grep -r $ec compiler/* --exclude-dir=rustc_error_codes`" ]
then
echo $ec
false
fi
done
```
i.e. these error codes appear nowhere in the compiler code and thus cannot be emitted.
r? ```@GuillaumeGomez```
Currently, we only point at the span of the macro argument. When the
macro call is itself generated by another macro, this can make it
difficult or impossible to determine which macro is responsible for
producing the error.
This commit fixes an issue not found during #84988 where rustdoc is used
to document cross-platform intrinsics but it was requiring that
functions which use `#[target_feature]` are `unsafe` erroneously, even
if they're WebAssembly specific. Rustdoc today, for example, already has
a special case where it enables annotations like
`#[target_feature(enable = "simd128")]` on platforms other than
WebAssembly. The purpose of this commit is to relax the "require all
`#[target_feature]` functions are `unsafe`" requirement for all targets
whenever rustdoc is running, enabling all targets to fully document
other targets, such as WebAssembly, where intrinsics functions aren't
always `unsafe`.
