py/mpstate.h: Only include sys.path/argv objects in state when enabled.

The mp_sys_path_obj and mp_sys_argv_obj objects are only used by the
runtime and accessible from Python if MICROPY_PY_SYS is enabled.  So
exclude them from the runtime state if this option is disabled.

Signed-off-by: Damien George <damien@micropython.org>

py/mpconfig.h

@@ -1308,7 +1308,7 @@ typedef double mp_float_t;
 
 // Whether to initialise "sys.path" and "sys.argv" to their defaults in mp_init()
 #ifndef MICROPY_PY_SYS_PATH_ARGV_DEFAULTS
-#define MICROPY_PY_SYS_PATH_ARGV_DEFAULTS (1)
+#define MICROPY_PY_SYS_PATH_ARGV_DEFAULTS (MICROPY_PY_SYS)
 #endif
 
 // Whether to provide "sys.maxsize" constant

py/mpstate.h

@@ -153,10 +153,12 @@ typedef struct _mp_state_vm_t {
     // dictionary for the __main__ module
     mp_obj_dict_t dict_main;
 
+    #if MICROPY_PY_SYS
     // If MICROPY_PY_SYS_PATH_ARGV_DEFAULTS is not enabled then these two lists
     // must be initialised after the call to mp_init.
     mp_obj_list_t mp_sys_path_obj;
     mp_obj_list_t mp_sys_argv_obj;
+    #endif
 
     // dictionary for overridden builtins
     #if MICROPY_CAN_OVERRIDE_BUILTINS