py/emitbc: Remove/refactor unreachable code, to improve coverage.

py/emitbc.c

@@ -302,15 +302,6 @@ STATIC void emit_write_bytecode_byte_signed_label(emit_t *emit, byte b1, mp_uint
     c[2] = bytecode_offset >> 8;
 }
 
-#if MICROPY_EMIT_NATIVE
-STATIC void mp_emit_bc_set_native_type(emit_t *emit, mp_uint_t op, mp_uint_t arg1, qstr arg2) {
-    (void)emit;
-    (void)op;
-    (void)arg1;
-    (void)arg2;
-}
-#endif
-
 void mp_emit_bc_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scope) {
     emit->pass = pass;
     emit->stack_size = 0;
@@ -408,9 +399,7 @@ void mp_emit_bc_end_pass(emit_t *emit) {
     }
 
     // check stack is back to zero size
-    if (emit->stack_size != 0) {
-        mp_printf(&mp_plat_print, "ERROR: stack size not back to zero; got %d\n", emit->stack_size);
-    }
+    assert(emit->stack_size == 0);
 
     emit_write_code_info_byte(emit, 0); // end of line number info
 
@@ -528,9 +517,10 @@ void mp_emit_bc_load_const_tok(emit_t *emit, mp_token_kind_t tok) {
         case MP_TOKEN_KW_FALSE: emit_write_bytecode_byte(emit, MP_BC_LOAD_CONST_FALSE); break;
         case MP_TOKEN_KW_NONE: emit_write_bytecode_byte(emit, MP_BC_LOAD_CONST_NONE); break;
         case MP_TOKEN_KW_TRUE: emit_write_bytecode_byte(emit, MP_BC_LOAD_CONST_TRUE); break;
-        no_other_choice:
-        case MP_TOKEN_ELLIPSIS: emit_write_bytecode_byte_obj(emit, MP_BC_LOAD_CONST_OBJ, MP_OBJ_FROM_PTR(&mp_const_ellipsis_obj)); break;
-        default: assert(0); goto no_other_choice; // to help flow control analysis
+        default:
+            assert(tok == MP_TOKEN_ELLIPSIS);
+            emit_write_bytecode_byte_obj(emit, MP_BC_LOAD_CONST_OBJ, MP_OBJ_FROM_PTR(&mp_const_ellipsis_obj));
+            break;
     }
 }
 
@@ -964,7 +954,7 @@ void mp_emit_bc_end_except_handler(emit_t *emit) {
 
 #if MICROPY_EMIT_NATIVE
 const emit_method_table_t emit_bc_method_table = {
-    mp_emit_bc_set_native_type,
+    NULL, // set_native_type is never called when emitting bytecode
     mp_emit_bc_start_pass,
     mp_emit_bc_end_pass,
     mp_emit_bc_last_emit_was_return_value,