[CMake] FIND_PROGRAM w/ CMake 2.8.2 and Cygwin

[Emmanuel Blot]

> Manu,
> please maintain the discussion on the mailing list as these is a general issue

Sure, sorry (actually I replied to your PM, I have not seen it did not
contain a cc: to the ML)

> if you are cross compiling, the target is not cygwin, so CYGWIN is not defined.

Ok, understood.

> However on cygwin both
> arm-eabi-gcc-4.5.2.exe
> arm-eabi-gcc-4.5.2
> are valid program names and you can call them.

It seems that FIND_PROGRAM fails to locate the .exe-less syntax when
cross-compiling is enabled, at least.

Cheers,
Manu