[llvm] [Convergence] allow non-convergent ops before entry and loop intrinsics (PR #65939)

[via llvm-commits]

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@@ -63,6 +63,8 @@ template <typename ContextT> class GenericConvergenceVerifier {
   // and not the token values.
   DenseMap<const InstructionT *, const InstructionT *> Tokens;
 
+  bool SeenFirstConvOp = false;
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ruiling wrote:

The value will not be reset across basic block, right?

https://github.com/llvm/llvm-project/pull/65939