Remove mp_obj_type_t.methods entry and use .locals_dict instead.

Originally, .methods was used for methods in a ROM class, and
locals_dict for methods in a user-created class.  That distinction is
unnecessary, and we can use locals_dict for ROM classes now that we have
ROMable maps.

This removes an entry in the bloated mp_obj_type_t struct, saving a word
for each ROM object and each RAM object.  ROM objects that have a
methods table (now a locals_dict) need an extra word in total (removed
the methods pointer (1 word), no longer need the sentinel (2 words), but
now need an mp_obj_dict_t wrapper (4 words)).  But RAM objects save a
word because they never used the methods entry.

Overall the ROM usage is down by a few hundred bytes, and RAM usage is
down 1 word per user-defined type/class.

There is less code (no need to check 2 tables), and now consistent with
the way ROM modules have their tables initialised.

Efficiency is very close to equivaluent.

1 files changed, 9 insertions, 7 deletions

diff --git a/stm/exti.c b/stm/exti.c
index 1484b622e..5b8c694a8 100644
--- a/stm/exti.c
+++ b/stm/exti.c
@@ -9,6 +9,7 @@
 #include "mpconfig.h"
 #include "qstr.h"
 #include "obj.h"
+#include "map.h"
 #include "runtime.h"
 #include "nlr.h"
 
@@ -226,14 +227,15 @@ static MP_DEFINE_CONST_FUN_OBJ_1(exti_obj_enable_obj,  exti_obj_enable);
 static MP_DEFINE_CONST_FUN_OBJ_1(exti_obj_disable_obj, exti_obj_disable);
 static MP_DEFINE_CONST_FUN_OBJ_1(exti_obj_swint_obj,   exti_obj_swint);
 
-static const mp_method_t exti_methods[] = {
-    { MP_QSTR_line,  &exti_obj_line_obj },
-    { MP_QSTR_enable,  &exti_obj_enable_obj },
-    { MP_QSTR_disable,  &exti_obj_disable_obj },
-    { MP_QSTR_swint,  &exti_obj_swint_obj },
-    { MP_QSTR_NULL, NULL },
+STATIC const mp_map_elem_t exti_locals_dict_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR_line), (mp_obj_t) &exti_obj_line_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_enable), (mp_obj_t) &exti_obj_enable_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_disable), (mp_obj_t) &exti_obj_disable_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_swint), (mp_obj_t) &exti_obj_swint_obj },
 };
 
+STATIC MP_DEFINE_CONST_DICT(exti_locals_dict, exti_locals_dict_table);
+
 static mp_obj_t exti_regs(void) {
     printf("EXTI_IMR   %08lx\n", EXTI->IMR);
     printf("EXTI_EMR   %08lx\n", EXTI->EMR);
@@ -317,7 +319,7 @@ const mp_obj_type_t exti_obj_type = {
     { &exti_meta_obj_type },
     .name = MP_QSTR_Exti,
     .print = exti_obj_print,
-    .methods = exti_methods,
+    .locals_dict = (mp_obj_t)&exti_locals_dict,
 };
 
 void exti_init(void) {