[RFA/mingw32] environment variables are case-insensitive on win32

[Eli Zaretskii]

> Date: Fri, 30 Nov 2012 15:08:44 +0100
> From: Jerome Guitton <guitton@adacore.com>
> Cc: gdb-patches@sourceware.org
> 
> Eli Zaretskii (eliz@gnu.org):
> 
> > Thanks.  But why did you exclude Cygwin?
> 
> Cygwin seems to be case-sensitive:
> 
> guitton@kerel ~
> $ export FooBar=Bar
> 
> guitton@kerel ~
> $ export FooBAR=BAR
> 
> guitton@kerel ~
> $ echo $FooBar
> Bar
> 
> guitton@kerel ~
> $ echo $FooBAR
> BAR

This is Bash, not Cygwin.  What happens if you define an environment
variable outside of a Cygwin program, and then use getenv in a Cygwin
program with different letter-case?