don't expect to be able to reparse arbitrary system headers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40511 91177308-0d34-0410-b5e6-96231b3b80d8

test/Parser/char-literal-printing.c

@@ -1,4 +1,4 @@
-// RUN: clang -parse-ast-print %s 2>&1 | clang -parse-ast-print
+// RUN: clang -parse-ast-print %s
 
 #include <stddef.h>