[llvm] [llvm][ARM] Add a cortex-m4f alignment hazard recognizer (PR #126991)

[Jon Roelofs via llvm-commits]

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@@ -622,6 +626,12 @@ void ARMPassConfig::addPreEmitPass2() {
     // Identify valid eh continuation targets for Windows EHCont Guard.
     addPass(createEHContGuardCatchretPass());
   }
+
+  // Enable the hazard recognizer for cortex-m4f at -O2 or higher.
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jroelofs wrote:

We probably should turn this off at `-Oz`. That would need to be handled by the hazard recognizer itself, since those are per-function attributes.

https://github.com/llvm/llvm-project/pull/126991