Testing - Add Windows ARM64 build and test support (#1135)

- Introduces new Windows ARM64 jobs in the multi-platform workflow (build, test, retest, gtest).
- Extends composite GitHub actions with a `target-arch` input and adds ARM64 Mesa llvmpipe setup for headless rendering.
- Adjusts architecture reporting (`dversion`) and updates one mesh regression test with ARM64-specific expected values; updates a DE enum definition to avoid an MSVC ARM64 LTCG miscompile.

.github/workflows/build-and-test-multiplatform.yml

@@ -88,6 +88,23 @@ jobs:
         artifact-name: install-windows-x64
         github-token: ${{ secrets.GITHUB_TOKEN }}
 
+  prepare-and-build-windows-arm64:
+    name: Prepare and Build on Windows with MSVC (ARM64)
+    runs-on: windows-11-arm
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4.2.2
+
+    - name: Build OCCT
+      uses: ./.github/actions/build-occt
+      with:
+        platform: windows
+        compiler: msvc
+        target-arch: arm64
+        artifact-name: install-windows-arm64
+        github-token: ${{ secrets.GITHUB_TOKEN }}
+
   prepare-and-build-macos-x64:
     name: Prepare and Build on macOS with Clang (x64)
     runs-on: macos-15
@@ -160,6 +177,25 @@ jobs:
         test-directory-name: windows-x64
         test-script: .github/actions/testgrid/testwindows.tcl
 
+  test-windows-arm64:
+    name: Test on Windows (arm64)
+    runs-on: windows-11-arm
+    needs: prepare-and-build-windows-arm64
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4.2.2
+
+    - name: Run tests
+      uses: ./.github/actions/run-tests
+      with:
+        platform: windows
+        compiler: msvc
+        target-arch: arm64
+        install-artifact-name: install-windows-arm64
+        test-directory-name: windows-arm64
+        test-script: .github/actions/testgrid/testwindowsarm.tcl
+
   retest-windows-x64:
     name: Regression Test on Windows (x64)
     runs-on: windows-2025
@@ -178,6 +214,25 @@ jobs:
         results-artifact-name: results-windows-x64
         test-directory-name: windows-x64
 
+  retest-windows-arm64:
+    name: Regression Test on Windows (arm64)
+    runs-on: windows-11-arm
+    needs: test-windows-arm64
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4.2.2
+      
+    - name: Run retest
+      uses: ./.github/actions/retest-failures
+      with:
+        platform: windows
+        compiler: msvc
+        target-arch: arm64
+        install-artifact-name: install-windows-arm64
+        results-artifact-name: results-windows-arm64
+        test-directory-name: windows-arm64
+
   test-macos-x64:
     name: Test on macOS (x64)
     runs-on: macos-15
@@ -267,6 +322,24 @@ jobs:
         install-artifact-name: install-windows-x64
         artifact-suffix: x64
 
+  run-gtest-windows-arm64:
+    name: Run GTest on Windows with MSVC (arm64)
+    needs: prepare-and-build-windows-arm64
+    runs-on: windows-11-arm
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4.2.2
+
+    - name: Run GTests
+      uses: ./.github/actions/run-gtest
+      with:
+        platform: windows
+        compiler: msvc
+        target-arch: arm64
+        install-artifact-name: install-windows-arm64
+        artifact-suffix: arm64
+
   run-gtest-macos-x64:
     name: Run GTest on macOS with Clang (x64)
     needs: prepare-and-build-macos-x64