ci: add cross build for x86

.builds/alpine.yml

@@ -15,18 +15,25 @@ tasks:
       cd libliftoff
       CC=gcc meson build-gcc/ --fatal-meson-warnings -Db_coverage=true
       CC=clang meson build-clang/ --fatal-meson-warnings -Db_sanitize=address,undefined -Db_lundef=false
+      meson build-x86/ --fatal-meson-warnings --buildtype=debugoptimized --cross-file=.builds/x86-linux-gnu.ini
   - build-gcc: |
       cd libliftoff
       ninja -C build-gcc/
   - build-clang: |
       cd libliftoff
       ninja -C build-clang/
+  - build-x86: |
+      cd libliftoff
+      ninja -C build-x86/
   - test-gcc: |
       cd libliftoff
       ninja -C build-gcc/ test
   - test-clang: |
       cd libliftoff
       ninja -C build-clang/ test
+  - test-x86: |
+      cd libliftoff
+      ninja -C build-x86/ test
   - coverage: |
       cd libliftoff
       ninja -C build-gcc/ coverage-html

.builds/x86-linux-gnu.ini

@@ -0,0 +1,26 @@
+[binaries]
+c = '/usr/bin/gcc'
+cpp = '/usr/bin/g++'
+ar = '/usr/bin/gcc-ar'
+strip = '/usr/bin/strip'
+pkgconfig = '/usr/bin/pkgconf'
+llvm-config = '/usr/bin/llvm-config32'
+
+[properties]
+c_args = ['-m32']
+c_link_args = ['-m32']
+cpp_args = ['-m32']
+cpp_link_args = ['-m32']
+pkg_config_path = ['/usr/lib32/pkgconfig']
+pkg_config_libdir = ['/usr/lib32/pkgconfig']
+
+[paths]
+prefix = '/usr'
+libdir = 'lib32'
+bindir = 'bin'
+
+[host_machine]
+system = 'linux'
+cpu_family = 'x86'
+cpu = 'i686'
+endian = 'little'