[llvm] [AMDGPU] Replace amdgpu-num-* attributes with stress options (PR #213924)

[Matt Arsenault via llvm-commits]

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@@ -538,38 +550,9 @@ unsigned GCNSubtarget::getBaseMaxNumSGPRs(
   unsigned MaxNumSGPRs = getMaxNumSGPRs(WavesPerEU.first, false);
   unsigned MaxAddressableNumSGPRs = getMaxNumSGPRs(WavesPerEU.first, true);
 
-  // Check if maximum number of SGPRs was explicitly requested using
-  // "amdgpu-num-sgpr" attribute.
-  unsigned Requested =
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arsenm wrote:

Can you split this into 2 parts? The patch to migrate all of the test uses to use the flags should be separate. If we're going to rip out the IR attribute handling, the clang side attribute probably needs to turn into a warning 

https://github.com/llvm/llvm-project/pull/213924