Fix broken mingw x86_64 buildscript

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

@@ -3,6 +3,7 @@ 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++)
+find_program(CMAKE_RC_COMPILER NAMES x86_64-w64-mingw32-windres)
 
 if(NOT CMAKE_C_COMPILER)
 	message(FATAL_ERROR "Failed to find CMAKE_C_COMPILER.")
@@ -11,3 +12,7 @@ endif()
 if(NOT CMAKE_CXX_COMPILER)
 	message(FATAL_ERROR "Failed to find CMAKE_CXX_COMPILER.")
 endif()
+
+if(NOT CMAKE_RC_COMPILER)
+        message(FATAL_ERROR "Failed to find CMAKE_RC_COMPILER.")
+endif()