mlpack: build shared library

mingw-w64-mlpack/PKGBUILD

@@ -41,11 +41,14 @@ build() {
     _build_type="Release"
   fi
 
+  LDFLAGS+=" -Wl,--export-all-symbols"
+
   MSYS2_ARG_CONV_EXCL="-DCMAKE_INSTALL_PREFIX=" \
   ${MINGW_PREFIX}/bin/cmake.exe -Wno-dev \
     -G"Ninja" \
     -DCMAKE_INSTALL_PREFIX=${MINGW_PREFIX} \
     -DCMAKE_BUILD_TYPE=${_build_type} \
+    -DBUILD_SHARED_LIBS=ON \
     -DBUILD_TESTS=OFF \
     -DBUILD_PYTHON_BINDINGS=OFF \
     ../${_src}