[PATCH] Expand Microsoft Windows notes in Host/Target specific installation notes

[Danny Smith]

> +@item PW32: i386-pc-pw32: See @uref{http://pw32.sourceforge.net/} for more
> +information.

AFAICT this project has been inactive since  May 2001.  No one has
*ever* represented this project with a gcc patch or bug report or
testsuite result.  WTF is it doing in config.gcc?


> +@item UWIN: Support for this target has been removed for legal reasons.
> +@end itemize

Another deprecation. It will soon disappear from config.gcc.   No one
has supported since Mumit Khan bcame inactive.  Is it really worth
stirring up  'legal reasons' when a target has no support anyway?

Otherwise this is fine with me

Danny