Add win build for CI

scripts/build_win_pkgconf.bat

@@ -0,0 +1,15 @@
+@ECHO OFF
+SETLOCAL
+SET PREFIX=%CD%\clib
+IF NOT EXIST cbuild (
+    MD cbuild || EXIT /B 1
+)
+CD cbuild || EXIT /B 1
+git clone --depth 1 "https://github.com/pkgconf/pkgconf" || EXIT /B %ERRORLEVEL%
+CD pkgconf || EXIT /B %ERRORLEVEL%
+meson setup build --prefix %PREFIX% -Dtests=false || EXIT /B %ERRORLEVEL%
+meson compile -C build || EXIT /B %ERRORLEVEL%
+meson install -C build || EXIT /B %ERRORLEVEL%
+CD %PREFIX%\bin || EXIT /B 1
+COPY /Y pkgconf.exe pkg-config.exe || EXIT /B %ERRORLEVEL%
+ENDLOCAL