Fix Cast

Avoid a cast-away-const error by properly using const_cast<>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172558 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/CXXInheritance.cpp b/lib/AST/CXXInheritance.cpp
index 5083a01..0e0b35d 100644
--- a/lib/AST/CXXInheritance.cpp
+++ b/lib/AST/CXXInheritance.cpp
@@ -118,7 +118,8 @@
 }
 
 bool CXXRecordDecl::isProvablyNotDerivedFrom(const CXXRecordDecl *Base) const {
-  return forallBases(BaseIsNot, (void*) Base->getCanonicalDecl());
+  return forallBases(BaseIsNot,
+                     const_cast<CXXRecordDecl *>(Base->getCanonicalDecl()));
 }
 
 bool