Modify Linux build script to also build for ARM64

.ci/linux.sh

@@ -1,5 +1,28 @@
 #!/bin/sh -ex
 
+if [ "$TARGET" = "arm64-appimage" ]; then
+mkdir build && cd build
+CC=aarch64-linux-gnu-gcc-11 CXX=aarch64-linux-gnu-g++-11 cmake .. -G Ninja \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_C_COMPILER_LAUNCHER=ccache \
+    -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+    -DENABLE_ASM=OFF \
+    -DENABLE_QT_TRANSLATION=ON \
+    -DCITRA_ENABLE_COMPATIBILITY_REPORTING=ON \
+    -DCITRA_ENABLE_BUNDLE_TARGET=OFF \
+    -DENABLE_COMPATIBILITY_LIST_DOWNLOAD=ON \
+    -DUSE_DISCORD_PRESENCE=ON
+ninja
+
+DESTDIR="$PWD/AppDir" ninja install
+mv ./AppDir/usr/local/* ./AppDir/usr
+rm -rf ./AppDir/usr/local
+sed -e s/PrefersNonDefaultGPU=true//g -i ./AppDir/usr/share/applications/citra-qt.desktop
+7z a AppDir.7z AppDir
+mkdir bundle
+mv AppDir.7z ./bundle
+else
+
 mkdir build && cd build
 cmake .. -G Ninja \
     -DCMAKE_BUILD_TYPE=Release \
@@ -18,3 +41,4 @@ fi
 ccache -s
 
 ctest -VV -C Release
+fi