[clang] [clang][codegen] Add a verifier IR pass before any further passes. (PR #68015)

[John McCall via cfe-commits]

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@@ -923,6 +923,8 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
 
   ModulePassManager MPM;
+  // Add a verifier pass, before any other passes, to catch CodeGen issues.
+  MPM.addPass(VerifierPass());
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rjmccall wrote:

I agree that it's valuable to do verification right out of IR generation, but the verifier pass is pretty heavyweight, and I don't think we want to be doing it unconditionally in release builds.  There's a reason there's an option to enable/disable it.

https://github.com/llvm/llvm-project/pull/68015