[clang] [CIR] Upstream initial for-loop support (PR #132266)

[Erich Keane via cfe-commits]

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@@ -52,6 +52,15 @@ class CIRBaseBuilderTy : public mlir::OpBuilder {
     return cir::BoolAttr::get(getContext(), getBoolTy(), state);
   }
 
+  /// Create a for operation.
+  cir::ForOp createFor(
+      mlir::Location loc,
+      llvm::function_ref<void(mlir::OpBuilder &, mlir::Location)> condBuilder,
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erichkeane wrote:

Is this intentionally missing the init?  `ForStmt` has an Init, Condition, Step, and Body, but this handles only 3.

https://github.com/llvm/llvm-project/pull/132266