py/bc0.h: Add comment that MP_BC_MAKE_CLOSURE/_DEFARGS take extra byte.
#define MP_BC_MAKE_FUNCTION (0x60) // uint
#define MP_BC_MAKE_FUNCTION_DEFARGS (0x61) // uint
-#define MP_BC_MAKE_CLOSURE (0x62) // uint
-#define MP_BC_MAKE_CLOSURE_DEFARGS (0x63) // uint
+#define MP_BC_MAKE_CLOSURE (0x62) // uint; byte
+#define MP_BC_MAKE_CLOSURE_DEFARGS (0x63) // uint; byte
#define MP_BC_CALL_FUNCTION (0x64) // uint
#define MP_BC_CALL_FUNCTION_VAR_KW (0x65) // uint
#define MP_BC_CALL_METHOD (0x66) // uint
