Added missing const.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163477 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/ASTContext.h b/include/clang/AST/ASTContext.h
index 299067d..93ed1c4 100644
--- a/include/clang/AST/ASTContext.h
+++ b/include/clang/AST/ASTContext.h
@@ -1844,7 +1844,7 @@
   // Per C99 6.2.5p6, for every signed integer type, there is a corresponding
   // unsigned integer type.  This method takes a signed type, and returns the
   // corresponding unsigned integer type.
-  QualType getCorrespondingUnsignedType(QualType T);
+  QualType getCorrespondingUnsignedType(QualType T) const;
 
   //===--------------------------------------------------------------------===//
   //                    Type Iterators.
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 7942e10..d64ed11 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -6830,7 +6830,7 @@
   return (unsigned)getTypeSize(T);
 }
 
-QualType ASTContext::getCorrespondingUnsignedType(QualType T) {
+QualType ASTContext::getCorrespondingUnsignedType(QualType T) const {
   assert(T->hasSignedIntegerRepresentation() && "Unexpected type");
   
   // Turn <4 x signed int> -> <4 x unsigned int>