[clang] [CIR] Initial support for emitting coroutine body (PR #161616)

[Andy Kaylor via cfe-commits]

================
@@ -0,0 +1,85 @@
+//===----- CGCoroutine.cpp - Emit CIR Code for C++ coroutines -------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code dealing with C++ code generation of coroutines.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CIRGenFunction.h"
+#include "mlir/Support/LLVM.h"
+#include "clang/AST/StmtCXX.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/CIR/Dialect/IR/CIRTypes.h"
+
+using namespace clang;
+using namespace clang::CIRGen;
+
+struct clang::CIRGen::CGCoroData {
+  // Stores the __builtin_coro_id emitted in the function so that we can supply
+  // it as the first argument to other builtins.
+  cir::CallOp coroId = nullptr;
+};
+
+// Defining these here allows to keep CGCoroData private to this file.
+CIRGenFunction::CGCoroInfo::CGCoroInfo() {}
+CIRGenFunction::CGCoroInfo::~CGCoroInfo() {}
+
+static void createCoroData(CIRGenFunction &cgf,
+                           CIRGenFunction::CGCoroInfo &curCoro,
+                           cir::CallOp coroId) {
+  if (curCoro.data) {
+    llvm_unreachable("EmitCoroutineBodyStatement called twice?");
+    return;
+  }
+
+  curCoro.data = std::unique_ptr<CGCoroData>(new CGCoroData);
----------------
andykaylor wrote:

```suggestion
  curCoro.data = std::make_unique<CGCoroData>();
```

https://github.com/llvm/llvm-project/pull/161616