[openmp] [clang] [OpenMP] Cleanup and fixes for ABI agnostic DeviceRTL (PR #71234)

[Saiyedul Islam via cfe-commits]

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@@ -17468,19 +17468,19 @@ Value *EmitAMDGPUImplicitArgPtr(CodeGenFunction &CGF) {
 /// Emit code based on Code Object ABI version.
 /// COV_4    : Emit code to use dispatch ptr
 /// COV_5    : Emit code to use implicitarg ptr
-/// COV_NONE : Emit code to load a global variable "llvm.amdgcn.abi.version"
+/// COV_NONE : Emit code to load a global variable "__oclc_ABI_version"
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saiislam wrote:

`oclc_ABI_version` already exist in the upstream. And, it contains the exact same information as `llvm.amdgcn.abi.version` was supposed to store. So, I removed the latter with the former.

This patch is ensuring that DeviceRTL is indeed ABI agnostic.

I agree with your suggestion that it would be great to not deal with these things in the driver.

https://github.com/llvm/llvm-project/pull/71234