[clang] [CIR] Upstream the initial BlockAddressOp implementation (PR #168151)

[Henrich Lauko via cfe-commits]

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@@ -3778,6 +3778,12 @@ mlir::LogicalResult CIRToLLVMVAArgOpLowering::matchAndRewrite(
   return mlir::success();
 }
 
+mlir::LogicalResult CIRToLLVMBlockAddressOpLowering::matchAndRewrite(
+    cir::BlockAddressOp op, OpAdaptor adaptor,
+    mlir::ConversionPatternRewriter &rewriter) const {
+  return mlir::failure();
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xlauko wrote:

Why no lowering here?

https://github.com/llvm/llvm-project/pull/168151