[llvm] [AIX] Add git revision to .file string (PR #88164)

[David Tenty via llvm-commits]

================
@@ -0,0 +1,13 @@
+; Check that the git revision is contained in the assembly/object files
+
+; RUN: cd %S && git rev-parse HEAD > %t
----------------
daltenty wrote:

Hmm, seems like there are no existing tests which directly call `git` this way. I'm not sure if that's a problem, but I wonder if there's any other way to retrieve this?

https://github.com/llvm/llvm-project/pull/88164