Add configuration files and patches for R, SDL2, SDL3, Tk, and Vala

- Introduced `r.toml` for R package configuration, including build flags and dependencies.
- Added `sdl2-compat.toml` for SDL2 compatibility layer with SDL3, specifying build and runtime dependencies.
- Created a patch for SDL3 to handle cases when XInput2 is not available, ensuring compatibility.
- Added `sdl3.toml` for SDL3 configuration, including build flags and dependencies.
- Introduced `tk.toml` for Tk configuration, detailing build flags and runtime dependencies.
- Added a patch for Vala to ensure POSIX compliance in the test runner script, improving portability.

extra/sdl2-compat/sdl2-compat.toml

@@ -0,0 +1,30 @@
+[build]
+type = "cmake"
+
+[build.flags]
+build_dir = "build"
+configure = ["-G Ninja"]
+post_install = [ 'ln -s sdl2-compat.pc "$DESTDIR/usr/lib/pkgconfig/sdl2.pc"' ]
+no-delete-static = true
+
+[dependencies]
+build = [
+    "cmake",
+    "ninja",
+]
+runtime = [
+    "sdl3",
+    "glibc",
+]
+
+[package]
+description = "An SDL2 compatibility layer that uses SDL3 behind the scenes"
+homepage = "https://github.com/libsdl-org/sdl2-compat"
+license = "Zlib"
+name = "sdl2-compat"
+version = "2.32.64"
+
+[[source]]
+extract_dir = "$name-$version"
+sha256 = "b2fa522e7bb08113534904b3dc2d2f7ff7b0c259224d86c12374d5b4a4027930"
+url = "https://github.com/libsdl-org/sdl2-compat/releases/download/release-$version/sdl2-compat-$version.tar.gz"