bug#24956: 26.0.50; On Windows, setting PATH in compilation-environment has no effect

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@users.sourceforge.net>
> Date: Fri, 18 Nov 2016 17:11:22 -0500
> Cc: Óscar Fuentes <ofv@wanadoo.es>, 24956@debbugs.gnu.org
> 
> Here is a patch.

Thanks.

Two comments:

  . I'd rather have the WINDOWSNT-specific code separate (on w32.c),
    so perhaps the for-loop you modified could be left intact, and
    instead we perform an additional pass over Vprocess_environment,
    after it is already copied, to replace these two variables with
    their upper-case equivalents, in that special code on w32.c.

  . If you didn't already, please verify that these 2 variables in the
    Emacs's own environment are also upcased, because otherwise I
    think we will hit more such problems.