Added toolchain files for cross-compiling to Windows

build-scripts/cmake-toolchain-mingw64-i686.cmake

@@ -0,0 +1,13 @@
+set(CMAKE_SYSTEM_NAME Windows)
+set(CMAKE_SYSTEM_PROCESSOR x86)
+
+find_program(CMAKE_C_COMPILER NAMES i686-w64-mingw32-gcc)
+find_program(CMAKE_CXX_COMPILER NAMES i686-w64-mingw32-g++)
+
+if(NOT CMAKE_C_COMPILER)
+	message(FATAL_ERROR "Failed to find CMAKE_C_COMPILER.")
+endif()
+
+if(NOT CMAKE_CXX_COMPILER)
+	message(FATAL_ERROR "Failed to find CMAKE_CXX_COMPILER.")
+endif()

build-scripts/cmake-toolchain-mingw64-x86_64.cmake

@@ -0,0 +1,13 @@
+set(CMAKE_SYSTEM_NAME Windows)
+set(CMAKE_SYSTEM_PROCESSOR x86_64)
+
+find_program(CMAKE_C_COMPILER NAMES x86_64-w64-mingw32-gcc)
+find_program(CMAKE_CXX_COMPILER NAMES x86_64-w64-mingw32-g++)
+
+if(NOT CMAKE_C_COMPILER)
+	message(FATAL_ERROR "Failed to find CMAKE_C_COMPILER.")
+endif()
+
+if(NOT CMAKE_CXX_COMPILER)
+	message(FATAL_ERROR "Failed to find CMAKE_CXX_COMPILER.")
+endif()