Update llvm-c headers for Version 11.0.1

src/llvm-c/IRReader.h

@@ -14,11 +14,10 @@
 #ifndef LLVM_C_IRREADER_H
 #define LLVM_C_IRREADER_H
 
+#include "ExternC.h"
 #include "Types.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+LLVM_C_EXTERN_C_BEGIN
 
 /**
  * Read LLVM IR from a memory buffer and convert it into an in-memory Module
@@ -33,8 +32,6 @@ LLVMBool LLVMParseIRInContext(LLVMContextRef ContextRef,
                               LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutM,
                               char **OutMessage);
 
-#ifdef __cplusplus
-}
-#endif
+LLVM_C_EXTERN_C_END
 
 #endif