[compiler-rt] Fix test ifdefs and XFAILs

[mstorsjo]

This fixes the ifdefs added in
e9e166e; we need to include int_lib.h first before we can expect these defines to be set.

Also remove the XFAILs for aarch64 windows. As this test now became a no-op on platforms that lack CRT_HAS_128BIT or CRT_HAS_F128 (aarch64 windows lacks the latter), it no longer fails.

[mstorsjo]

This should fix failing tests that I've run into in my nightly build at https://github.com/mstorsjo/llvm-mingw/actions/runs/17993746384/job/51211649698.

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[DavidSpickett]

The code is new to me but after inspecting the headers, the change makes sense.

I'll let @ahatanak take a look too.

[ahatanak]

Ah, I didn't realize I'd unconditionally disabled the tests. Thanks for catching the error.

[alazarev]

It breaks https://lab.llvm.org/buildbot/#/builders/66/builds/19787

[mstorsjo]

It breaks https://lab.llvm.org/buildbot/#/builders/66/builds/19787

Hmm, right. So this is essentially e9e166e which enabled these tests to run in these configurations (where they didn't use to run before), where they now show up as broken.

I guess the best first step is to revert both this and e9e166e, and then @ahatanak can look into what's needed to make this configuration not break, if they would be relanded.

[mstorsjo]

I pushed a revert in f7e8350.

[rorth]

The test also breaks the Solaris/amd64 bot:

• FAIL: Builtins-x86_64-sunos :: fixunstfdi_test.c:

  Exit Code: 1
  
  Command Output (stdout):
  --
  error in __fixunstfdi(0X1.0000000000000000P+0) = 0, expected 1
  

• FAIL: Builtins-x86_64-sunos :: multc3_test.c:

  /var/llvm/tools/clang/stage2-bins/projects/compiler-rt/test/builtins/Unit/X86_64SunOSConfig/Output/multc3_test.c.script: line 1: 18353 Segmentation Fault
  

[ahatanak]

The signature of the function declared in the test file is different from the builtin's signature.

declaration in the test: long double _Complex __multc3(long double __a, long double __b, long double __c, long double __d);
builtin: Qcomplex __multc3(fp_t a, fp_t b, fp_t c, fp_t d).

I think we should skip the test if the return type or the argument types don't match.