forgot header guard😅

Author: paperchalice

llvm/include/llvm/CodeGen/GCEmptyBasicBlocks.h

@@ -5,6 +5,8 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
+#ifndef LLVM_CODEGEN_GCEMPTYBASICBLOCKS_H
+#define LLVM_CODEGEN_GCEMPTYBASICBLOCKS_H
 
 #include "llvm/CodeGen/MachinePassManager.h"
 
@@ -17,3 +19,5 @@ class GCEmptyBasicBlocksPass : public PassInfoMixin<GCEmptyBasicBlocksPass> {
 };
 
 } // namespace llvm
+
+#endif // LLVM_CODEGEN_GCEMPTYBASICBLOCKS_H