Attempt automatic detection

Author: tstellar

.github/workflows/release-binaries.yml

@@ -298,12 +298,13 @@ jobs:
         #ls -l /c/vcpkg/packages/libxml2_x64-windows-static/include/libxml2/libxml
         # There were some issues on the ARM64 MacOS runners with trying to build x86 object,
         # so we need to set some extra cmake flags to disable this.
+        # -DLIBXML2_LIBRARIES=/c/vcpkg/packages/libxml2_x64-windows-static/lib/libxml2.lib \
+        # -DLIBXML2_INCLUDE_DIR=/c/vcpkg/packages/libxml2_x64-windows-static/include/libxml2 \
         cmake --debug-trycompile  -G Ninja -S llvm -B ${{ steps.setup-stage.outputs.build-prefix }}/build \
             ${{ needs.prepare.outputs.target-cmake-flags }} \
             -DLLVM_ENABLE_LIBXML2=FORCE_ON \
-            -DLIBXML2_LIBRARIES=/c/vcpkg/packages/libxml2_x64-windows-static/lib/libxml2.lib \
-            -DLIBXML2_INCLUDE_DIR=/c/vcpkg/packages/libxml2_x64-windows-static/include/libxml2 \
             -DLIBXML2_DEFINITIONS=-DLIBXML_STATIC \
+            -DCMAKE_PREFIX_PATH=/c/vcpkg/packages/libxml2_x64-windows-static/ \
             -C clang/cmake/caches/Release.cmake \
             -DBOOTSTRAP_BOOTSTRAP_CPACK_PACKAGE_FILE_NAME="${{ needs.prepare.outputs.release-binary-basename }}"