[clang] [compiler-rt] [llvm] Reland "[PGO][AMDGPU] Add basic HIP offload PGO support (#177665)" (PR #201499)

[Yaxun Liu via cfe-commits]

yxsamliu wrote:

I've split this reland into two smaller PRs as suggested, and closed the design question by making the ROCm support a separate, self-contained library:

- #201606 — compiler-rt: relands the runtime and adds the opt-in clang_rt.profile_rocm library (a /MD superset of clang_rt.profile, so the base library stays /MT and unchanged).
- #201607 — clang/LLVM: relands the compiler-side instrumentation and adds the driver wiring to link clang_rt.profile_rocm for HIP device PGO. Depends on #201606.

Both are green on premerge (including Windows). I'm closing this PR in favor of the two above. @zmodem @jhuber6 @ronlieb could you take a look when you have a chance? #201606 should land first.

https://github.com/llvm/llvm-project/pull/201499