The tests that were in `src/test/` have been moved to `tests/`, so the paths
given by the suggestion tool should reflect this.

Signed-off-by: ozkanonur <work@onurozkan.dev>

We've been relying on a custom patch to add `MCSubtargetInfo::getCPUTable`
for `rustc --print target-cpus`, and just printing that it's not supported
on external LLVM builds. LLVM `main` now has `getAllProcessorDescriptions`
that can replace ours, so now we try to use that. In addition, the fallback
path can at least print the native and default cpu options.

There were also some mismatches in the function signatures here between
`LLVM_RUSTLLVM` and otherwise; this is now mitigated by sharing these
functions and only using cpp to adjust the function bodies.

…mulacrum

Fix the test directories suggested by `./x.py suggest`

It seems that these paths were correct when rust-lang#106249 was being written, but since then rust-lang#106458 has been merged (moving `src/test/` to `tests/`), making the tool's suggestions incorrect.

…imulacrum

Make more ConstProp tests unit.

…p-scripts, r=Mark-Simulacrum

check bootstrap scripts syntax

Fails bootstrapping if `x`/`x.ps1` scripts are not valid. Currently, it keeps executing lines until the invalid one.

Output LLVM optimization remark kind in `-Cremark` output

Since rust-lang#90833, the optimization remark kind has not been printed. Therefore it wasn't possible to easily determine from the log (in a programmatic way) which remark kind was produced. I think that the most interesting remarks are the missed ones, which can lead users to some code optimization.

Maybe we could also change the format closer to the "old" one:
```
note: optimization remark for tailcallelim at /checkout/src/libcore/num/mod.rs:1:0: marked this call a tail call candidate
```

I wanted to programatically parse the remarks so that they could work e.g. with https://github.com/OfekShilon/optview2. However, now that I think about it, probably the proper solution is to tell rustc to output them to YAML and then use the YAML as input for the opt remark visualization tools. The flag for enabling this does not seem to work though (rust-lang#96705 (comment)).

Still I think that it's good to output the remark kind anyway, it's an important piece of information.

r? ```@tmiasko```

asm: loongarch64: Implementation of clobber_abi

r? ```@Amanieu```

…Simulacrum

Expand the LLVM coverage of `--print target-cpus`

We've been relying on a custom patch to add `MCSubtargetInfo::getCPUTable`
for `rustc --print target-cpus`, and just printing that it's not supported
on external LLVM builds. LLVM `main` now has `getAllProcessorDescriptions`
that can replace ours, so now we try to use that. In addition, the fallback
path can at least print the native and default cpu options.

There were also some mismatches in the function signatures here between
`LLVM_RUSTLLVM` and otherwise; this is now mitigated by sharing these
functions and only using cpp to adjust the function bodies.

Check arguments length in trivial diagnostic lint

Fixes rust-lang#111280