Update llvm-c headers for Version 11.0.1

src/llvm-c/Types.h

@@ -15,10 +15,9 @@
 #define LLVM_C_TYPES_H
 
 #include "DataTypes.h"
+#include "ExternC.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+LLVM_C_EXTERN_C_BEGIN
 
 /**
  * @defgroup LLVMCSupportTypes Types and Enumerations
@@ -172,8 +171,6 @@ typedef struct LLVMOpaqueBinary *LLVMBinaryRef;
  * @}
  */
 
-#ifdef __cplusplus
-}
-#endif
+LLVM_C_EXTERN_C_END
 
 #endif