Allow to set XT subsystem when producing binaries

sdk/cmake/xtchain.cmake

@@ -82,4 +82,8 @@ function(set_subsystem MODULE SUBSYSTEM)
     string(TOUPPER ${SUBSYSTEM} SUBSYSTEM)
     add_module_linker_flags(${MODULE} "/SUBSYSTEM:${SUBSYSTEM},6.03")
     add_module_linker_flags(${MODULE} "/VERSION:6.03")
+    if(${ARGC} EQUAL 3)
+        set(XTSUBSYSTEM ${ARGN})
+        add_custom_command(TARGET ${MODULE} POST_BUILD COMMAND exetool "$<TARGET_FILE:${MODULE}>" ${XTSUBSYSTEM})
+    endif()
 endfunction()