[llvm] [IR] Initial introduction of memset_pattern (PR #97583)

[Craig Topper via llvm-commits]

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@@ -1263,6 +1263,46 @@ class MemSetInlineInst : public MemSetInst {
   }
 };
 
+/// This is the base class for memset.pattern
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topperc wrote:

experimental.memsest.pattern?

https://github.com/llvm/llvm-project/pull/97583