[llvm] AMDGPU: Return legal addressmode correctly for flat scratch (PR #71494)

[via llvm-commits]

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@@ -1357,6 +1357,13 @@ bool SITargetLowering::isLegalGlobalAddressingMode(const AddrMode &AM) const {
   return isLegalMUBUFAddressingMode(AM);
 }
 
+bool SITargetLowering::isLegalFlatScratchAddressingMode(
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ruiling wrote:

Done in the latest commit.

https://github.com/llvm/llvm-project/pull/71494