ci: Setup Travis to build and run cross-compiled tests

Author: arteymix

.travis.yml

@@ -15,21 +15,23 @@ env:
     - VALAC=valac-0.28
     - VALAC=valac-0.30
     - VALAC=valac VALAFLAGS=--fatal-warnings
+    - VALAC=valac CROSS=mingw-w64-i686
+    - VALAC=valac CROSS=mingw-w64-x86-64
 
 before_install:
     - sudo add-apt-repository --yes ppa:vala-team
     - sudo apt-get update --quiet
     - sudo apt-get install --yes --force-yes ${VALAC} libglib2.0-bin
       libglib2.0-dev libsoup2.4-dev libfcgi-dev python3-pip gcovr libgee-0.8-dev
       libctpl-dev libjson-glib-dev libmemcached-dev libmarkdown2-dev
-      liblua5.2-dev valgrind
+      liblua5.2-dev valgrind $([[ -n ${CROSS} ]] && echo gcc-${CROSS} wine1.6)
     - pip3 install meson sphinx sphinx_rtd_theme PyYAML
     - wget https://github.com/ninja-build/ninja/releases/download/v1.6.0/ninja-linux.zip
     - unzip ninja-linux.zip -d ${HOME}/.local/bin
 
 before_script:
     - mkdir build
-    - meson -D b_coverage=true -D enable_examples=true . build
+    - meson -D b_coverage=true -D enable_examples=true $([[ -n ${CROSS} ]] && echo cross/${CROSS}.txt) . build
     - ninja -C build -v
     - ninja -C build -v docs/en