Fix libxml failure

.github/workflows/windows.yml

@@ -0,0 +1,62 @@
+name: windows
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  adapters:
+    name: Adapter specs on Windows (libxml)
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          submodules: "recursive"
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.3"
+          bundler-cache: false
+
+      - name: Install libxml2 and build tools via MSYS2
+        shell: cmd
+        run: |
+          C:\msys64\usr\bin\pacman.exe -S --needed --noconfirm ^
+            mingw-w64-ucrt-x86_64-libxml2 ^
+            mingw-w64-ucrt-x86_64-libiconv ^
+            mingw-w64-ucrt-x86_64-zlib ^
+            mingw-w64-ucrt-x86_64-ragel ^
+            mingw-w64-ucrt-x86_64-make ^
+            mingw-w64-ucrt-x86_64-gcc
+
+      - name: Put MSYS2 UCRT64 toolchain on PATH
+        shell: pwsh
+        run: |
+          "PATH=C:\msys64\ucrt64\bin;C:\msys64\usr\bin;$env:PATH" >> $env:GITHUB_ENV
+
+      - name: Configure libxml-ruby build
+        shell: pwsh
+        run: |
+          bundle config build.libxml-ruby --with-xml2-include=C:/msys64/ucrt64/include/libxml2 --with-xml2-lib=C:/msys64/ucrt64/lib --with-iconv-include=C:/msys64/ucrt64/include --with-iconv-lib=C:/msys64/ucrt64/lib
+
+      - name: Generate ragel / ruby-ll outputs in vendored forks
+        shell: pwsh
+        run: |
+          gem install ruby-ll --no-document
+          rake vendor:prepare
+
+      - name: Install dependencies
+        run: bundle install --jobs 4
+
+      - name: Compile vendored native extensions
+        run: bundle exec rake vendor:compile
+
+      - name: Run adapter specs
+        run: bundle exec rake spec:adapter

Gemfile

@@ -30,7 +30,8 @@ gem "rubocop-performance"
 gem "rubocop-rake"
 gem "rubocop-rspec"
 gem "simplecov", require: false
-gem "stackprof"
+# stackprof relies on POSIX signals (SIGPROF/sigaction) unavailable on Windows
+gem "stackprof" unless Gem.win_platform?
 gem "tempfile"
 
 # Needed by get_process_mem on Windows