MinGW and Cygwin support for sdl2-ttf

[jmid]

The sausage factory continues... 🧑‍🏭

I spotted a SDL2_ttf Windows failures recently on #28326 motivating this.

The installed MinGW packages are

• https://cygwin.com/packages/summary/mingw64-i686-SDL2_ttf.html
• https://cygwin.com/packages/summary/mingw64-x86_64-SDL2_ttf.html
• https://packages.msys2.org/base/mingw-w64-SDL2_ttf

The most exciting part is that the latter supports i686, compared to #28507

Again, while at it, I added Cygwin support based on https://cygwin.com/packages/summary/libSDL2_ttf-devel.html

I've tested the changes (incl. MSys2) with a self-PR here: jmid#10

[Copilot]

Pull Request Overview

This PR adds MinGW and Cygwin support for SDL2_ttf by creating architecture-specific MinGW packages and updating the main configuration to handle Windows cross-compilation scenarios.

• Creates separate MinGW packages for i686 and x86_64 architectures with appropriate pkg-config personalities
• Updates the main SDL2_ttf configuration to conditionally use pkgconf with MinGW personalities on Windows
• Adds Cygwin support with native SDL2_ttf package dependency

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
packages/conf-sdl2-ttf/conf-sdl2-ttf.1/opam	Updates build commands and dependencies to support MinGW cross-compilation and adds Cygwin depext
packages/conf-mingw-w64-sdl2-ttf-x86_64/conf-mingw-w64-sdl2-ttf-x86_64.1/opam	New package providing x86_64 MinGW SDL2_ttf support with Cygwin and MSys2 depexts
packages/conf-mingw-w64-sdl2-ttf-i686/conf-mingw-w64-sdl2-ttf-i686.1/opam	New package providing i686 MinGW SDL2_ttf support with Cygwin and MSys2 depexts

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