Use '-x' 'foo' instead of '-x=foo'.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90069 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Preprocessor/cxx_true.cpp b/test/Preprocessor/cxx_true.cpp
index 80aa04e..bca70c5 100644
--- a/test/Preprocessor/cxx_true.cpp
+++ b/test/Preprocessor/cxx_true.cpp
@@ -1,6 +1,6 @@
-/* RUN: clang-cc -E %s -x=c++ | grep block_1
-   RUN: clang-cc -E %s -x=c++ | not grep block_2
-   RUN: clang-cc -E %s -x=c | not grep block
+/* RUN: clang-cc -E %s -x c++ | grep block_1
+   RUN: clang-cc -E %s -x c++ | not grep block_2
+   RUN: clang-cc -E %s -x c | not grep block
 */
 
 #if true