Build and test 32bit and 64bit versions of the windows port using gcc
from mingw-w64. Note a bunch of tests which rely on floating point
math/printing have been disabled for now since they fail.
The number of registers used should be 10, not 12, to match the assembly
code in nlrx64.c. With this change the 64bit mingw builds don't need to
use the setjmp implementation, and this fixes miscellaneous crashes and
assertion failures as reported in #1751 for instance.
To avoid mistakes in the future where something gcc-related for Windows
only gets fixed for one particular compiler/environment combination,
make use of a MICROPY_NLR_OS_WINDOWS macro.
To make sure everything nlr-related is now ok when built with gcc this
has been verified with:
- unix port built with gcc on Cygwin (i686-pc-cygwin-gcc and
x86_64-pc-cygwin-gcc, version 6.4.0)
- windows port built with mingw-w64's gcc from Cygwin
(i686-w64-mingw32-gcc and x86_64-w64-mingw32-gcc, version 6.4.0)
and MSYS2 (like the ones on Cygwin but version 7.2.0)
Add some features which are already enabled in the unix port and
default to using the Python stack for scoped allocations: this can be
more performant in cases the heap is heavily used because for example
the memory needed for storing *args and **kwargs doesn't require
scanning the heap to find a free block.
For MSVC off_t is defined in sys/types.h but according to the comment
earlier in mpconfigport.h this cannot be included directly.
So just make off_t the same as mp_off_t.
This fixes the build for MSVC with MICROPY_STREAMS_POSIX_API
enabled because stream.h uses off_t.
This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.
