GHA: Promote macOS-arm64 cross-compilation job to full native job

.github/actions/1-setup/action.yml

@@ -121,8 +121,12 @@ runs:
       run: |
         set -euxo pipefail
         python3 --version
-        python3 -m pip install --user setuptools wheel
-        python3 -m pip install --user lit
+        if [[ '${{ runner.os }}-${{ inputs.arch }}' == 'macOS-arm64' ]]; then
+          brew install lit python-setuptools
+        else
+          python3 -m pip install --user setuptools wheel
+          python3 -m pip install --user lit
+        fi
         python3 -c "import lit.main; lit.main.main();" --version . | head -n 1
 
     # the druntime tests require GNU make

.github/workflows/main.yml

@@ -51,6 +51,19 @@ jobs:
               -DEXTRA_CXXFLAGS=-flto=full
             with_pgo: true
 
+          - job_name: macOS arm64
+            os: macos-14
+            arch: arm64
+            bootstrap_cmake_flags: >-
+              -DBUILD_LTO_LIBS=ON
+              -DD_COMPILER_FLAGS=-gcc=/usr/bin/c++
+            extra_cmake_flags: >-
+              -DBUILD_LTO_LIBS=ON
+              -DD_COMPILER_FLAGS="-gcc=/usr/bin/c++ -O -flto=full -defaultlib=phobos2-ldc-lto,druntime-ldc-lto -L-exported_symbol '-L__*' -L-w"
+              -DEXTRA_CXXFLAGS=-flto=full
+            with_pgo: true
+            llvm_version: 17.0.6 # FIXME: sporadic 'libc++abi: Pure virtual function called!' compiler crashes with LLVM 18 (see https://github.com/ldc-developers/ldc/pull/4604, https://github.com/ldc-developers/ldc/pull/4541)
+
           - job_name: Windows x64
             os: windows-2022
             arch: x64
@@ -76,17 +89,20 @@ jobs:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 90
     env:
-      MACOSX_DEPLOYMENT_TARGET: 10.12
+      MACOSX_DEPLOYMENT_TARGET: ${{ matrix.arch == 'arm64' && '11.0' || '10.12' }}
     steps:
       - uses: actions/checkout@v4
         with:
           submodules: true
           fetch-depth: 50
+      - name: 'macOS 14: Switch to Xcode v14.3.1'
+        if: matrix.os == 'macos-14'
+        run: sudo xcode-select -switch /Applications/Xcode_14.3.1.app
       - name: Install prerequisites
         uses: ./.github/actions/1-setup
         with:
           clang_version: ${{ runner.os == 'Windows' && '18.1.5' || env.CLANG_VERSION }}
-          llvm_version: ${{ env.LLVM_VERSION }}
+          llvm_version: ${{ matrix.llvm_version || env.LLVM_VERSION }}
           arch: ${{ matrix.arch }}
       - name: Build bootstrap LDC
         uses: ./.github/actions/2-build-bootstrap
@@ -160,19 +176,6 @@ jobs:
       matrix:
         include:
 
-          - job_name: macOS arm64
-            host_os: macos-11
-            os: osx
-            arch: arm64
-            bootstrap_cmake_flags: -DD_COMPILER_FLAGS=-gcc=/usr/bin/c++
-            # see native macOS job comment for extra flags (https://github.com/ldc-developers/ldc/issues/4462)
-            extra_cmake_flags: >-
-              -DBUILD_LTO_LIBS=ON
-              -DD_COMPILER_FLAGS="-O -flto=full -defaultlib=phobos2-ldc-lto,druntime-ldc-lto -L-exported_symbol '-L__*' -L-w"
-              -DEXTRA_CXXFLAGS=-flto=full
-            with_pgo: true
-            llvm_version: 17.0.6 # TODO
-
           - job_name: Android armv7a
             host_os: ubuntu-20.04
             os: android
@@ -191,8 +194,6 @@ jobs:
     name: ${{ matrix.job_name }}
     runs-on: ${{ matrix.host_os }}
     timeout-minutes: 60
-    env:
-      MACOSX_DEPLOYMENT_TARGET: 11.0
     steps:
       - uses: actions/checkout@v4
         with:
@@ -202,7 +203,7 @@ jobs:
         uses: ./.github/actions/1-setup
         with:
           clang_version: ${{ env.CLANG_VERSION }}
-          llvm_version: ${{ matrix.llvm_version || env.LLVM_VERSION }}
+          llvm_version: ${{ env.LLVM_VERSION }}
           arch: x86_64
       - name: Build bootstrap LDC
         uses: ./.github/actions/2-build-bootstrap
@@ -218,19 +219,14 @@ jobs:
         with:
           arch: ${{ matrix.arch }}
           os: ${{ matrix.os }}
-          llvm_version: ${{ matrix.llvm_version || env.LLVM_VERSION }}
+          llvm_version: ${{ env.LLVM_VERSION }}
           cmake_flags: ${{ matrix.extra_cmake_flags }}
           with_pgo: ${{ matrix.with_pgo }}
 
       - name: Install LDC & make portable
         uses: ./.github/actions/5-install
         with:
           cross_compiling: true
-      - name: 'macOS: Cross-compile iOS libraries, copy to install dir & extend ldc2.conf'
-        if: matrix.os == 'osx'
-        uses: ./.github/actions/5a-ios
-        with:
-          arch: ${{ matrix.arch }}
       - name: 'Android: Cross-compile ${{ matrix.android_x86_arch }} libraries & copy to install dir'
         if: matrix.os == 'android'
         uses: ./.github/actions/5a-android-x86
@@ -249,9 +245,7 @@ jobs:
     name: macOS universal
     runs-on: macos-latest
     timeout-minutes: 30
-    needs:
-      - build-native
-      - build-cross
+    needs: build-native
     steps:
       - uses: actions/checkout@v4
       - name: Merge x86_64 & arm64 packages to universal one