Enhance -fsyntax-only test of Carbon.h to also include testing for PTH.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61958 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Sema/carbon.c b/test/Sema/carbon.c
index 9c9c378..94a7075 100644
--- a/test/Sema/carbon.c
+++ b/test/Sema/carbon.c
@@ -1,4 +1,5 @@
-// RUN: clang %s -fsyntax-only -print-stats
+// RUN: clang %s -fsyntax-only -print-stats &&
+// RUN: clang -x c-header -o %t %s && clang -token-cache %t %s
 #ifdef __APPLE__
 #include <Carbon/Carbon.h>
 #endif