bug#19111: 25.0.50; 32 bits temacs.exe is linked with wrong image-base when built on 64 bit Windows host

[Dani Moncayo <dmoncayo@gmail.com>]

>> If MSYS2 provides both 32 and 64 bit build environments, each
>> environment should be configured so that 'uname -m' produced the
>> intended CPU architecture.
>
> You are asking the impossible: how can 'uname' know which code will be
> produced by a compiler that will be invoked by 'make'?

I may be misundertanding things; I'll try to explain what's on my
head.

As I see it, MSYS2 (either its 32 or 64-bit version) comes with two
ways of invoking bash: mingw32_shell.bat and mingw64_shell.bat.

IIUC, this gives the user two _build_ environments: one tuned for
building 32-bit MinGW programs and other for 64-bit.

So, if I enter the 32-bit _build_ environment and I build Emacs with a
plain 'configure && make', I'd expect it to work out of the box.  But
as we've seen, it doesn't.  Why? -> Because the canonical host
platform (picked up by default) has a wrong CPU.  And why? -> Because
the canonical _build_ platform picked (up by default) has a wrong CPU.
And why? -> because 'uname -m' gives 'x86_64' in a build environment
that pretends to be tuned for 32 bits.

-- 
Dani Moncayo