Revert a failed change

Author: YexuanXiao

clang/include/clang/AST/ASTContext.h

@@ -1950,7 +1950,7 @@ class ASTContext : public RefCountedBase<ASTContext> {
 
   /// Return the unique signed counterpart of
   /// the integer type corresponding to size_t.
-  QualType getSignedSizeType() const;
+  CanQualType getSignedSizeType() const;
 
   /// Return the unique type for "intmax_t" (C99 7.18.1.5), defined in
   /// <stdint.h>.

clang/lib/AST/ASTContext.cpp

@@ -6714,7 +6714,7 @@ QualType ASTContext::getSizeType() const {
 
 /// Return the unique signed counterpart of the integer type
 /// corresponding to size_t.
-QualType ASTContext::getSignedSizeType() const {
+CanQualType ASTContext::getSignedSizeType() const {
   return getFromTargetType(Target->getSignedSizeType());
 }