fix flag.cpp test

Author: rnk

clang/test/DebugInfo/KeyInstructions/flag.cpp

@@ -4,7 +4,7 @@
 
 //// Help.
 // RUN %clang --help | FileCheck %s --check-prefix=HELP
-// HELP: -gkey-instructions  Enable Key Instructions, which reduces the jumpiness of debug stepping in optimized C/C++ code in some debuggers. DWARF only. Implies -g.
+// HELP: -gkey-instructions  Enable Key Instructions, which reduces the jumpiness of debug stepping in optimized C/C++ code in some debuggers. DWARF only.
 
 // KEY-INSTRUCTIONS: "-gkey-instructions"
 // NO-KEY-INSTRUCTIONS-NOT: key-instructions