fix rdar://8823139, a crash on a comment in a preprocessed .s file
that contains the ## operator.

llvm-svn: 122946
diff --git a/clang/test/Preprocessor/assembler-with-cpp.c b/clang/test/Preprocessor/assembler-with-cpp.c
index 0543077..a9c4294 100644
--- a/clang/test/Preprocessor/assembler-with-cpp.c
+++ b/clang/test/Preprocessor/assembler-with-cpp.c
@@ -72,3 +72,8 @@
 11: T11(b)
 // CHECK-Identifiers-True: 11: #0
 
+
+// This should not crash
+// rdar://8823139
+# ##
+// CHECK-Identifiers-False: # ##