Switch a C-style cast over to a const_cast. No functionality change

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@137218 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CXCursor.cpp b/tools/libclang/CXCursor.cpp
index bbc9343..282f535 100644
--- a/tools/libclang/CXCursor.cpp
+++ b/tools/libclang/CXCursor.cpp
@@ -604,7 +604,7 @@
       Sema &S = unit->getSema();
       CodeCompletionAllocator *Allocator
         = unit->getCursorCompletionAllocator().getPtr();
-      CodeCompletionResult Result((IdentifierInfo *)MacroInfo);
+      CodeCompletionResult Result(const_cast<IdentifierInfo *>(MacroInfo));
       CodeCompletionString *String 
         = Result.CreateCodeCompletionString(S, *Allocator);
       return String;