Only run asm tests if they match the current codegen backend

[GuillaumeGomez]

Follow-up of #144125.

This PR changes compiletest so that asm tests are only run if they match the current codegen backend. To better reflect it, I renamed the tests/ui/asm folder into tests/ui/asm-llvm. Like that, we can add new asm tests for other backends if we want without needing to add extra code to compiletest.

Next step will be to use the new code annotations added in #144125 to ignore ui tests failing in cg_gcc until it's fixed on our side.

cc @antoyo @oli-obk
r? @Kobzol

[rustbot]

Some changes occurred in src/tools/compiletest

cc @jieyouxu

[rustbot]

There are changes to the tidy tool.

cc @jieyouxu

[rustbot]

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

The rustc-dev-guide subtree was changed. If this PR only touches the dev guide consider submitting a PR directly to rust-lang/rustc-dev-guide otherwise thank you for updating the dev guide with your changes.

cc @BoxyUwU, @jieyouxu, @Kobzol, @tshepang

[Kobzol]

Since this is mostly a compiletest thing, I'll delegate to jieyouxu: Maybe there's a better way to detect the asm directory in the UI test suite? Btw we should do something similar for tests/assembly and tests/codegen, right?

r? @jieyouxu

[rustbot]

jieyouxu is not on the review rotation at the moment.
They may take a while to respond.

[bjorn3]

These tests all are not LLVM specific. They test asm!() (which is backend agnostic, just target dependent), not --emit asm (which will produce different output depending on the backend).

[GuillaumeGomez]

Ah interesting! So I should move all asm!() tests into a tests/ui/asm folder which would be backend agnostic.

One question: should I move all tests containing asm! calls or is there another heuristic?

[bjorn3]

tests/ui/asm shouldn't contain any backend specific tests. Those are in tests/assembly and tests/codegen.

[GuillaumeGomez]

Oh I see, sorry I misunderstood. Then updating the other testsuites.

[bjorn3]

^

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

Some changes occurred in src/tools/opt-dist

cc @Kobzol

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo, @GuillaumeGomez

[GuillaumeGomez]

Applied suggestions.

[GuillaumeGomez]

Added the missing bits so I think I didn't forget anything this time.