[compiler-rt] [compiler-rt][pgo] Use mock coroutine header in instrprof-coroutine-profile.cpp (PR #214593)

[Douglas Yung via llvm-commits]

https://github.com/dyung approved this pull request.

I tried this on my bot that failed and it seems to fix the problem. Note that I am in the process of upgrading the bot to ubuntu 22, so this problem should go away after that (in case you check the bot and see it now passing instead of failing).

https://github.com/llvm/llvm-project/pull/214593