minor update to mingw-w64 build instructions.

Author: sezero

docs/README-windows.md

@@ -18,7 +18,9 @@ Details are here: https://github.com/libsdl-org/SDL/issues/5186
 
 ## MinGW-w64 compiler support
 
-SDL can be built with MinGW-w64 and CMake. First, you need to install and set up the MSYS2 environment, which provides the MinGW-w64 toolchain. Install MSYS2, typically to `C:\msys64`, and follow the instructions on the MSYS2 wiki to use the MinGW-w64 shell to update all components in the MSYS2 environment. This generally amounts to running `pacman -Syuu` from the mingw64 shell, but refer to MSYS2's documentation for more details. Once the MSYS2 environment has been updated, install the x86_64 MinGW toolchain from the mingw64 shell with the command `pacman -S mingw-w64-x86_64-toolchain`. (You can additionally install `mingw-w64-i686-toolchain` if you intend to build 32-bit binaries as well. The remainder of this section assumes you only want to build 64-bit binaries.)
+SDL can be built with MinGW-w64 and CMake. Minimum tested MinGW-w64 version is 8.0.3.
+
+On a Windows host, you first need to install and set up the MSYS2 environment, which provides the MinGW-w64 toolchain. Install MSYS2, typically to `C:\msys64`, and follow the instructions on the MSYS2 wiki to use the MinGW-w64 shell to update all components in the MSYS2 environment. This generally amounts to running `pacman -Syuu` from the mingw64 shell, but refer to MSYS2's documentation for more details. Once the MSYS2 environment has been updated, install the x86_64 MinGW toolchain from the mingw64 shell with the command `pacman -S mingw-w64-x86_64-toolchain`. (You can additionally install `mingw-w64-i686-toolchain` if you intend to build 32-bit binaries as well. The remainder of this section assumes you only want to build 64-bit binaries.)
 
 To build and install SDL, you can use PowerShell or any CMake-compatible IDE. First, install CMake, Ninja, and Git. These tools can be installed using any number of tools, such as the MSYS2's `pacman`, `winget`, `Chocolatey`, or by manually downloading and running the installers. Clone SDL to an appropriate location with `git` and run the following commands from the root of the cloned repository: