Rollup merge of #137074 - jieyouxu:rustc_abi, r=onur-ozkan

compiletest: add `{ignore,only}-rustc_abi-x86-sse2` directives

As requested in https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/compiletest.20target.20selection.20is.20way.20too.20rigid, cc `@RalfJung`

r? bootstrap (or compiler)

Author: matthiaskrgr

src/tests/directives.md

@@ -154,6 +154,7 @@ Some examples of `X` in `ignore-X` or `only-X`:
   `ignore-coverage-map`, `ignore-coverage-run`
 - When testing a dist toolchain: `dist`
   - This needs to be enabled with `COMPILETEST_ENABLE_DIST_TESTS=1`
+- The `rustc_abi` of the target: e.g. `rustc_abi-x86_64-sse2`
 
 The following directives will check rustc build settings and target
 settings: