[clang] [CIR] Build out AST consumer patterns to reach the entry point into CIRGen (PR #91007)

[Aaron Ballman via cfe-commits]

================
@@ -0,0 +1,59 @@
+//===- CIRGenerator.h - CIR Generation from Clang AST ---------------------===//
+//
+// 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 file declares a simple interface to perform CIR generation from Clang
+// AST
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CIRGENERATOR_H_
----------------
AaronBallman wrote:

The usual pattern would be to name this `LLVM_CLANG_CIR_CIRGENERATOR_H` (`project_subproject_directory_headername_extension`)

https://github.com/llvm/llvm-project/pull/91007