[llvm] [PGO] Fix zeroed estimated trip count (PR #167792)

[Joel E. Denny via llvm-commits]

jdenny-ornl wrote:

> LLVM Buildbot has detected a new failure on builder `openmp-offload-amdgpu-runtime-2` running on `rocm-worker-hw-02` while building `llvm` at step 6 "test-openmp".
> 
> Full details are available at: https://lab.llvm.org/buildbot/#/builders/10/builds/17980
> Here is the relevant piece of the build log for the reference

That one went green on the next run, so apparently it's a flaky bot/test.

I merged PR #169520 to try to address the other failures.

https://github.com/llvm/llvm-project/pull/167792