Fix buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195703 91177308-0d34-0410-b5e6-96231b3b80d8

test/CXX/drs/dr2xx.cpp

@@ -3,7 +3,7 @@
 // RUN: %clang_cc1 -std=c++1y %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
 
 // PR13819 -- __SIZE_TYPE__ is incompatible.
-typedef __SIZE_TYPE__ size_t; // expected-warning 0-1 {{extension}}
+typedef __SIZE_TYPE__ size_t; // expected-error 0-1 {{extension}}
 
 #if __cplusplus < 201103L
 #define fold(x) (__builtin_constant_p(x) ? (x) : (x))