Clean Windows build instructions

* CMake in MSYS2 now depends on Ninja and uses it by default, use it
  instead of Make as it has much easier to read output when doing
  parallel builds and doesn't need an extra program
* Ninja uses the maximum number of cores by default, so we don't have to
  run nproc --all
* We don't need mesa for its headers anymore

.github/workflows/build-windows.yml

@@ -27,19 +27,15 @@ jobs:
           update: true
 
     - name: Install dependencies
-      run: pacman -Sq --noconfirm git make pkgconf mingw-w64-x86_64-{cmake,mesa,SDL2,qt5-static,libslirp,libarchive,libepoxy,toolchain}
-
-    - name: Create build environment
-      working-directory: ${{runner.workspace}}
-      run: mkdir build
+      run: pacman -Sq --noconfirm git pkgconf mingw-w64-x86_64-{cmake,SDL2,qt5-static,libslirp,libarchive,toolchain}
 
     - name: Configure
-      working-directory: ${{runner.workspace}}/build
-      run: cmake $GITHUB_WORKSPACE -G 'MSYS Makefiles' -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DBUILD_STATIC=ON -DCMAKE_PREFIX_PATH=C:/tools/msys64/mingw64/qt5-static
+      working-directory: ${{runner.workspace}}
+      run: cmake -B build $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DBUILD_STATIC=ON -DCMAKE_PREFIX_PATH=C:/tools/msys64/mingw64/qt5-static
 
     - name: Make
       working-directory: ${{runner.workspace}}/build
-      run: make -j$(nproc --all)
+      run: cmake --build .
 
     - uses: actions/upload-artifact@v1
       with:

README.md

@@ -65,22 +65,22 @@ As for the rest, the interface should be pretty straightforward. If you have a q
    cd melonDS
    ```
 #### Dynamic builds (with DLLs)
-5. Install dependencies: `pacman -S make mingw-w64-x86_64-{cmake,mesa,SDL2,toolchain,qt5-base,qt5-svg,qt5-multimedia,libslirp,libarchive}`
+5. Install dependencies: `pacman -S mingw-w64-x86_64-{cmake,SDL2,toolchain,qt5-base,qt5-svg,qt5-multimedia,libslirp,libarchive}`
 6. Compile:
    ```bash
-   cmake -B build -G "MSYS Makefiles"
-   cmake --build build -j$(nproc --all)
+   cmake -B build
+   cmake --build build
    cd build
    ../tools/msys-dist.sh
    ```
 If everything went well, melonDS and the libraries it needs should now be in the `dist` folder.
 
 #### Static builds (without DLLs, standalone executable)
-5. Install dependencies: `pacman -S make mingw-w64-x86_64-{cmake,mesa,SDL2,toolchain,qt5-static,libslirp,libarchive}`
+5. Install dependencies: `pacman -S mingw-w64-x86_64-{cmake,SDL2,toolchain,qt5-static,libslirp,libarchive}`
 6. Compile:
    ```bash
-   cmake -B build -G 'MSYS Makefiles' -DBUILD_STATIC=ON -DCMAKE_PREFIX_PATH=/mingw64/qt5-static
-   cmake --build build -j$(nproc --all)
+   cmake -B build -DBUILD_STATIC=ON -DCMAKE_PREFIX_PATH=/mingw64/qt5-static
+   cmake --build build
    ```
 If everything went well, melonDS should now be in the `build` folder.