autofree: do not run in `builtin`

vlib/v/gen/cgen.v

@@ -1909,6 +1909,10 @@ fn (mut g Gen) gen_clone_assignment(val ast.Expr, right_sym table.TypeSymbol, ad
 }
 
 fn (mut g Gen) autofree_scope_vars(pos int) {
+	if g.is_builtin_mod {
+		// In `builtin` everything is freed manually.
+		return
+	}
 	g.writeln('// autofree_scope_vars($pos)')
 	// eprintln('> free_scope_vars($pos)')
 	scope := g.file.scope.innermost(pos)
@@ -1982,6 +1986,10 @@ fn (mut g Gen) autofree_var_call(free_fn_name string, v ast.Var) {
 	if v.is_autofree_tmp && !g.doing_autofree_tmp {
 		return
 	}
+	if v.name.contains('expr_write_1_') {
+		// TODO remove this temporary hack
+		return
+	}
 	if v.typ.is_ptr() {
 		g.writeln('\t${free_fn_name}(${c_name(v.name)}); // autofreed ptr var')
 	} else {

vlib/v/tests/valgrind/1.strings_and_arrays.v

@@ -224,8 +224,8 @@ fn main() {
 	str_replace2()
 	if_cond()
 	addition_with_tmp_expr()
-	if_expr()
-	return_if_expr()
+	q := if_expr()
+	s := return_if_expr()
 	free_inside_opt_block()
 	// free_map()
 	// loop_map()