Add SET_ADD opcode to VM.

py/runtime.c

@@ -1305,6 +1305,11 @@ py_obj_t rt_build_set(int n_args, py_obj_t *items) {
     return o;
 }
 
+py_obj_t rt_store_set(py_obj_t set, py_obj_t item) {
+    py_set_lookup(set, item, true);
+    return set;
+}
+
 py_obj_t rt_build_map(int n_args) {
     py_obj_base_t *o = m_new(py_obj_base_t, 1);
     o->kind = O_MAP;

py/runtime.h

@@ -119,9 +119,10 @@ py_obj_t rt_call_method_n(int n_args, const py_obj_t *args);
 py_obj_t rt_build_tuple(int n_args, py_obj_t *items);
 py_obj_t rt_build_list(int n_args, py_obj_t *items);
 py_obj_t rt_list_append(py_obj_t list, py_obj_t arg);
+py_obj_t rt_build_set(int n_args, py_obj_t *items);
+py_obj_t rt_store_set(py_obj_t set, py_obj_t item);
 py_obj_t rt_build_map(int n_args);
 py_obj_t rt_store_map(py_obj_t map, py_obj_t key, py_obj_t value);
-py_obj_t rt_build_set(int n_args, py_obj_t *items);
 py_obj_t rt_load_attr(py_obj_t base, qstr attr);
 void rt_load_method(py_obj_t base, qstr attr, py_obj_t *dest);
 void rt_store_attr(py_obj_t base, qstr attr, py_obj_t val);

py/vm.c

@@ -319,6 +319,13 @@ bool py_execute_byte_code_2(const byte *code, const byte **ip_in_out, py_obj_t *
                         *sp = obj1;
                         break;
 
+                    case PYBC_SET_ADD:
+                        DECODE_UINT;
+                        // I think it's guaranteed by the compiler that sp[unum] is a set
+                        rt_store_set(sp[unum], sp[0]);
+                        sp++;
+                        break;
+
                     case PYBC_MAKE_FUNCTION:
                         DECODE_UINT;
                         PUSH(rt_make_function_from_id(unum));