py/objtype: Don't expose mp_obj_instance_attr().

mp_obj_is_instance_type() can be used instead to check for instance types.

py/objtype.c

@@ -764,7 +764,7 @@ STATIC bool mp_obj_instance_store_attr(mp_obj_t self_in, qstr attr, mp_obj_t val
     }
 }
 
-void mp_obj_instance_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
+STATIC void mp_obj_instance_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
     if (dest[0] == MP_OBJ_NULL) {
         mp_obj_instance_load_attr(self_in, attr, dest);
     } else {

py/objtype.h

@@ -42,9 +42,6 @@ typedef struct _mp_obj_instance_t {
 mp_obj_instance_t *mp_obj_new_instance(const mp_obj_type_t *cls, const mp_obj_type_t **native_base);
 #endif
 
-// this needs to be exposed for MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE to work
-void mp_obj_instance_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest);
-
 // these need to be exposed so mp_obj_is_callable can work correctly
 bool mp_obj_instance_is_callable(mp_obj_t self_in);
 mp_obj_t mp_obj_instance_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args);

py/vm.c

@@ -336,7 +336,7 @@ dispatch_loop:
                     MARK_EXC_IP_SELECTIVE();
                     DECODE_QSTR;
                     mp_obj_t top = TOP();
-                    if (mp_obj_get_type(top)->attr == mp_obj_instance_attr) {
+                    if (mp_obj_is_instance_type(mp_obj_get_type(top))) {
                         mp_obj_instance_t *self = MP_OBJ_TO_PTR(top);
                         mp_uint_t x = *ip;
                         mp_obj_t key = MP_OBJ_NEW_QSTR(qst);
@@ -434,7 +434,7 @@ dispatch_loop:
                     MARK_EXC_IP_SELECTIVE();
                     DECODE_QSTR;
                     mp_obj_t top = TOP();
-                    if (mp_obj_get_type(top)->attr == mp_obj_instance_attr && sp[-1] != MP_OBJ_NULL) {
+                    if (mp_obj_is_instance_type(mp_obj_get_type(top)) && sp[-1] != MP_OBJ_NULL) {
                         mp_obj_instance_t *self = MP_OBJ_TO_PTR(top);
                         mp_uint_t x = *ip;
                         mp_obj_t key = MP_OBJ_NEW_QSTR(qst);