[cmd] Revert -MD flag skip
We should rather consider build actions containing -MD flag as
compilation because besides emitting precompilation infos, it also
accomplishes compilation.
@@ -246,7 +246,7 @@ INCLUDE_OPTIONS_MERGED = \
re.compile('(' + '|'.join(INCLUDE_OPTIONS_MERGED) + ')')
-PRECOMPILATION_OPTION = re.compile('-(E|M[G|T|Q|F|J|P|V|M|D]*)$')
+PRECOMPILATION_OPTION = re.compile('-(E|M[G|T|Q|F|J|P|V|M]*)$')
# Match for all of the compiler flags.
CLANG_OPTIONS = re.compile('.*')
