Comments followed by bare words in ifdefs no longer parse

[dburgener]

Prior to a7f658f the following policy parsed successfully, now it does not:

ifdef(`foo',`
        # comment
        bare_word
')

The reason this could be valid policy is if bare_word is an m4_macro being expanded. As a workaround, bare_word could be treated like an interface call as bare_word(). I'm open to saying this is a wontfix if the consensus is that this isn't syntax we want/need to support, but the fact that we previously parsed it makes me lean towards parsing it. I haven't had time to look into what the issue is or how easy it would be to fix yet.