RFC/RFT: split up pexecute.c

[DJ Delorie]

> You mean a patch to put it back the way it was before?  Previously,
> although there was a CYGWIN conditional in pexecute.c it was not
> actually used in the normal case unless the user specifically defined
> _WIN32.  Perhaps, that's not an ideal situation but this change
> introduces a change in behavior for cygwin since it is now exercising
> code that previously had not been commonly used.

Oh, I thought you meant you were going to get around to fixing the
code.  Yes, that does sound confusing.  Why wasn't the obsolete code
removed "back when" ?

Sounds like just configure.in needs a tweak, then?