CI: Add cross-compiled macOS ARM64 step

WIP

.gitlab-ci.yml

@@ -186,7 +186,7 @@ msys2-mingw64:
     paths:
       - "${CI_PROJECT_DIR}/_build/gtkdll.tar.gz"
 
-macos:
+macos-x86_64:
   extends: .only-default
   only:
     - branches@GNOME/gtk
@@ -215,6 +215,39 @@ macos:
     paths:
       - "${CI_PROJECT_DIR}/_build/meson-logs"
 
+macos-arm64:
+  extends: .only-default
+  only:
+    - branches@GNOME/gtk
+  stage: build
+  tags:
+    - macos
+  needs: []
+  before_script:
+    - bash .gitlab-ci/show-info-osx.sh
+    - pip3 install --user meson==0.60.3
+    - pip3 install --user ninja
+    - export PATH=/Users/gitlabrunner/Library/Python/3.7/bin:$PATH
+    - export MESON_FORCE_BACKTRACE=1
+    # Cross-compiling needs to force Meson not to look into default
+    # paths for libraries
+    - export PKG_CONFIG_LIBDIR="./_build/lib/pkgconfig"
+  script:
+    - meson --cross-file .gitlab-ci/cross-compile/macos-arm64.txt
+            -Dx11-backend=false
+            -Dbroadway-backend=true
+            -Dmacos-backend=true
+            -Dmedia-gstreamer=disabled
+            -Dintrospection=disabled
+            -Dcpp_std=c++11
+            -Dpixman:tests=disabled
+            _build
+    - ninja -C _build
+  artifacts:
+    when: always
+    paths:
+      - "${CI_PROJECT_DIR}/_build/meson-logs"
+
 vs2017-x64:
   extends: .only-default
   # TODO: Uncomment this when ready to merge.

.gitlab-ci/cross-compile/macos-arm64.txt

@@ -0,0 +1,24 @@
+[host_machine]
+system = 'darwin'
+cpu_family = 'aarch64'
+cpu = 'arm64'
+endian = 'little'
+
+[binaries]
+c = ['clang']
+cpp = ['clang++']
+objc = ['clang']
+objcpp = ['clang++']
+ar = ['ar']
+strip = ['strip']
+pkgconfig = ['pkg-config']
+
+[built-in options]
+c_args = ['-arch', 'arm64', '-mmacosx-version-min=11.0']
+cpp_args = ['-stdlib=libc++', '-arch', 'arm64', '-mmacosx-version-min=11.0']
+objc_args = ['-arch', 'arm64', '-mmacosx-version-min=11.0']
+objcpp_args = ['-stdlib=libc++', '-arch', 'arm64', '-mmacosx-version-min=11.0']
+c_link_args = ['-arch', 'arm64', '-mmacosx-version-min=11.0']
+cpp_link_args = ['-arch', 'arm64', '-mmacosx-version-min=11.0']
+objc_link_args = ['-arch', 'arm64', '-mmacosx-version-min=11.0']
+objcpp_link_args = ['-arch', 'arm64', '-mmacosx-version-min=11.0']