Re: odd -J complaint from make on netbsd-11

["Simon J. Gerraty" <sjg%crufty.net@localhost>]

>>The patch below will check for both progname and "make" (if progname !=
>>"make") in the expanded (if needed) commands.
>>It does a much better job of spotting "make" as a word (preceded by '/'
>>or space, and followed by space or nul.
>>
>>This change however results in a *lot* more (19) changes to test results.

On further pondering, trying to expand commands before we have read alll
makefiles is not a good idea.  So the call to MaybeSubMake should be
move to when we first run a target (if OP_SUBMAKE not already set)
hopefully when expanding it anyway.  That way we reduce overhead (not
expanding commands for targets that never run, and for those that do,
avoid expanding multiple times).

I expect that will reduce the test churn a little too.