Patch/windres: Fix handling of hex-notation escape sequences in quoted strings

[Ian Lance Taylor]

Danny Smith <danny_smith_0000@yahoo.co.nz> writes:

> The following windres bug was reported to mingw.org by Tom Bonner
> 
> 
>  The resource
>      MENUITEM "\xd6ffnen",        IDM_OPEN	
>  doesn't work as it should do, instead I have to use
>  something like
>      MENUITEM "\xd6" "ffnen",        IDM_OPEN	
>  (The latter one isn't compatible with MSVC6).
>  The problem seems to be the double-f, which is
>  interpreted as belonging to the previous escape sequence.

The goal is to implement whatever the MS tools do.  The current code
permits an unlimited number of digits after the \x, since that is what
C does and that was my understanding of what the MS tools did.  But if
they do not--if they only take two characters after the \x--then this
change is approved.  Please do confirm that that is what MS does,
though.

Ian