[clang] [llvm] [mlir] [InferAttrs] Mark errnomem-setting libcalls as such (PR #124742)

[Antonio Frighetto via llvm-commits]

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@@ -554,6 +579,7 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setOnlyReadsMemory(F, 0);
+    Changed |= setOnlyAccessesErrnoMemory(F);
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antoniofrighetto wrote:

Hmm, shouldn’t marking all pointer arguments as readonly be semantically equivalent to having ArgMem: Ref?

https://github.com/llvm/llvm-project/pull/124742