Add support for #pragma mark, which shouldn't warn about bogus tokens.

llvm-svn: 45212
diff --git a/clang/test/Lexer/pragma-mark.c b/clang/test/Lexer/pragma-mark.c
new file mode 100644
index 0000000..388fef5
--- /dev/null
+++ b/clang/test/Lexer/pragma-mark.c
@@ -0,0 +1,11 @@
+// RUN: clang %s -fsyntax-only -verify
+
+// Lexer diagnostics shouldn't be included in #pragma mark.
+#pragma mark Mike's world
+_Pragma("mark foo ' bar")
+
+#define X(S) _Pragma(S)
+X("mark foo ' bar")
+
+int i;
+