[clang] [CIR] Upstream support for while and do..while loops (PR #133157)

[Andy Kaylor via cfe-commits]

================
@@ -759,6 +761,84 @@ def BrCondOp : CIR_Op<"brcond",
   }];
 }
 
+//===----------------------------------------------------------------------===//
+// While & DoWhileOp
+//===----------------------------------------------------------------------===//
+
+class WhileOpBase<string mnemonic> : CIR_Op<mnemonic, [
+  LoopOpInterface,
+  NoRegionArguments,
+]> {
+  defvar isWhile = !eq(mnemonic, "while");
+  let summary = "C/C++ " # !if(isWhile, "while", "do-while") # " loop";
+  let builders = [
+    OpBuilder<(ins "llvm::function_ref<void(mlir::OpBuilder &, mlir::Location)>":$condBuilder,
----------------
andykaylor wrote:

Yeah, we haven't been fitting the .td files in 80 columns, though I have also thought we probably should do so.

It looks like tablegen will accept it like this:
```
  let builders = [
    OpBuilder<(ins "llvm::function_ref<void(mlir::OpBuilder &, "
                                           "mlir::Location)>":$condBuilder,
                   "llvm::function_ref<void(mlir::OpBuilder &, "
                                           "mlir::Location)>":$bodyBuilder), [{
        mlir::OpBuilder::InsertionGuard guard($_builder);
        $_builder.createBlock($_state.addRegion());
      }] # !if(isWhile, [{
        condBuilder($_builder, $_state.location);
        $_builder.createBlock($_state.addRegion());
        bodyBuilder($_builder, $_state.location);
      }], [{
        bodyBuilder($_builder, $_state.location);
        $_builder.createBlock($_state.addRegion());
        condBuilder($_builder, $_state.location);
      }])>
  ];
```
What do you think? Is that readable?

https://github.com/llvm/llvm-project/pull/133157