Constify argument of Preprocessor::getMacroInfoHistory and propagate to
callers, removing unneeded const_cast


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172372 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 3237d22..33811d0 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -6233,7 +6233,7 @@
 
   ASTUnit *Unit = static_cast<ASTUnit *>(TU->TUData);
   Preprocessor &PP = Unit->getPreprocessor();
-  MacroInfo *MI = PP.getMacroInfoHistory(const_cast<IdentifierInfo*>(&II));
+  MacroInfo *MI = PP.getMacroInfoHistory(&II);
   while (MI) {
     if (MacroDefLoc == MI->getDefinitionLoc())
       return MI;