testsuite result updates for x86_64-w64-mingw32

[Óscar Fuentes]

Eric Botcazou <ebotcazou@adacore.com> writes:

>> About the Ada compiler: it doesn't build on i686-w64-mingw32. It is
>> the reason why MSYS2 is stuck with 7.3 for 32 bits.
>
> Why doesn't it build?  Because of PR ada/81878?

More specifically:

xgcc.exe: internal compiler error: Aborted signal terminated program gnat1

If you are interested on analyzing this problem, ask and I'll try to
help as far as my time permits.