Allow cross build for windows using mingw32

- Build the compiler using CMake for:
  - Linux native gcc
  - Windows using mingw32
diff --git a/contrib/mingw32-toolchain.cmake b/contrib/mingw32-toolchain.cmake
new file mode 100644
index 0000000..3dfb1a5
--- /dev/null
+++ b/contrib/mingw32-toolchain.cmake
@@ -0,0 +1,19 @@
+# CMake mingw32 cross compile toolchain file

+

+# the name of the target operating system

+SET(CMAKE_SYSTEM_NAME Windows)

+

+# which compilers to use for C and C++

+SET(CMAKE_C_COMPILER i586-mingw32msvc-gcc)

+SET(CMAKE_CXX_COMPILER i586-mingw32msvc-g++)

+SET(CMAKE_RC_COMPILER i586-mingw32msvc-windres)

+

+# here is the target environment located

+SET(CMAKE_FIND_ROOT_PATH /usr/i586-mingw32msvc)

+

+# adjust the default behaviour of the FIND_XXX() commands:

+# search headers and libraries in the target environment, search 

+# programs in the host environment

+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)

+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)

+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)