[clang] [CIR] Recognize strlen in the IdiomRecognizer pass (PR #210400)

[Erich Keane via cfe-commits]

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@@ -2280,6 +2280,8 @@ void LoweringPreparePass::runOnOp(mlir::Operation *op) {
     lowerArrayDtor(arrayDtor);
   } else if (auto findOp = mlir::dyn_cast<cir::StdFindOp>(op)) {
     lowerStdOp(findOp);
+  } else if (auto strlenOp = mlir::dyn_cast<cir::StrLenOp>(op)) {
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erichkeane wrote:

I wonder if we should have a common base-class here for these ops, so we can just do a single `if` here and only a single option on the `runOnOperation` below.

https://github.com/llvm/llvm-project/pull/210400