add windows support for gmp

[ecoezen]

Is your feature request related to a problem? Please describe.

existing gmp package does not support windows. conan recipe made it work on windows. would be great if xmake also supports it.

Describe the solution you'd like

https://github.com/conan-io/conan-center-index/tree/master/recipes/gmp

Describe alternatives you've considered

using add_requires("conan::gmp/6.3.0", {alias = "gmp"}) but due to internal disables in packages like cgal, it is kinda hopeless.

Additional context

No response

[luadebug]

This is pretty much MSYS2/MinGW solution rather Windows solution?
https://github.com/conan-io/conan-center-index/blob/master/recipes/gmp/all/conanfile.py#L83-L84

[SirLynix]

Some packages such as ffmpeg need a msys2 environment and tooling (generating makefile using msvc).

See https://github.com/xmake-io/xmake-repo/blob/dev/packages/f/ffmpeg/xmake.lua#L113-L124 and https://github.com/xmake-io/xmake-repo/blob/dev/packages/f/ffmpeg/xmake.lua#L213-L279

this is the main reason we have a msys2 package

[luadebug]

Some packages such as ffmpeg need a msys2 environment and tooling (generating makefile using msvc).

See https://github.com/xmake-io/xmake-repo/blob/dev/packages/f/ffmpeg/xmake.lua#L113-L124 and https://github.com/xmake-io/xmake-repo/blob/dev/packages/f/ffmpeg/xmake.lua#L213-L279

this is the main reason we have a msys2 package

1. I think we need to figure out what is behind ar-wrapper first and how to use it within xmake toolset. https://github.com/conan-io/conan-center-index/blob/master/recipes/gmp/all/conanfile.py#L128
2. Also yasm-wrapper is another interesting wrapper. Do we need it as well?
3. How would it differ MT / MD / MTd / MDd runtimes and debug/release builds in such case?
4. Which one of MSYS2 MSYSTEM should be used?