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

[Eli Friedman via llvm-commits]

================
@@ -672,13 +703,15 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setOnlyReadsMemory(F, 0);
+    Changed |= setOnlyAccessesErrnoMemory(F);
----------------
efriedma-quic wrote:

Yes, the argument should be readonly.  Might need to reformulate the setter functions to make clear what this is doing...

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