Profiling still doesn't seem to work properly, but this at least hooks up the library and eases completing whatever is missing.
This change breaks building/testing the compiler with CLANG_DEFAULT_LINKER set to lld. Was this intentional? What should people do if they want to use CLANG_DEFAULT_LINKER and run the test suite?
It wasn't intentional. Originally I added -fuse-ld=lld to the test, but this broke buildbots that didn't have lld available. My fixup in rC353922 avoided this by removing the -fuse-ld=lld (where I noted in the commit message that I guess that it would break such configurations). At that point I thought the other tests in this same file also would be equally broken in such a setup then. But I see that most other tests use -fuse-ld=ld, to work around this. (This option doesn't check if the named tool exists, contrary to -fuse-ld=<any-other-string>.)
But if a linker named <triplet>-ld exists, that will be used instead, so I'll need to make the regex a bit looser as well. I'll commit a fix for this soon.