Don't shortcut macro expansion of non-parameter macros. It won't work once we have more kinds of expansion items than strings and arguments, viz., magic tokens for __FILE__ and __LINE__ and so on. (separate version of this applied against Joerg's changes, because we need to revert some of them)

#define STOP */
#define START /*

/*
 * blah blah blah STOP fnord START goop moop
 */