Auto merge of #145384 - ywxt:parallel-tests, r=jieyouxu

Add more tests for the parallel rustc

At the moment, the parallel frontend test cases are severely lacking. Althought some reported issues have been resolved, they haven't been added into the tests.

This PR arranges the resolved ICE issues and adds tests for them.

Whether it is worthwhile to add a separate test suite for the paralel frontend still requires futher discussion. But we are trying coveraging issues being resolved through capability of the existing UI test suite.

Discussion: [Zulip](https://rust-lang.zulipchat.com/#narrow/channel/233931-t-compiler.2Fmajor-changes/topic/Proposal.20for.20a.20dedicated.20test.20suite.20for.20t.E2.80.A6.20compiler-team.23906)

Related issues:
- rust-lang/rust#120760
- rust-lang/rust#124423 fixed by rust-lang/rust#140358
- rust-lang/rust#127971 fxied by rust-lang/rust#140358
- rust-lang/rust#120601 fixed by rust-lang/rust#127311

cc `@jieyouxu`

Author: bors

src/tests/directives.md

@@ -111,6 +111,7 @@ for more details.
 | `forbid-output`                   | A pattern which must not appear in stderr/`cfail` output                                                                 | `ui`, `incremental`                          | Regex pattern                                                                           |
 | `run-flags`                       | Flags passed to the test executable                                                                                      | `ui`                                         | Arbitrary flags                                                                         |
 | `known-bug`                       | No error annotation needed due to known bug                                                                              | `ui`, `crashes`, `incremental`               | Issue number `#123456`                                                                  |
+| `compare-output-by-lines`         | Compare the output by lines, rather than as a single string                                                              | All                                          | N/A                                                                                     |
 
 [^check_stdout]: presently <!-- date-check: Oct 2024 --> this has a weird quirk
     where the test binary's stdout and stderr gets concatenated and then

src/tests/ui.md

@@ -95,6 +95,7 @@ will check for output files:
   [Normalization](#normalization)).
 - `dont-check-compiler-stderr` — Ignores stderr from the compiler.
 - `dont-check-compiler-stdout` — Ignores stdout from the compiler.
+- `compare-output-by-lines` — Some tests have non-deterministic orders of output, so we need to compare by lines.
 
 UI tests run with `-Zdeduplicate-diagnostics=no` flag which disables rustc's
 built-in diagnostic deduplication mechanism. This means you may see some