fast: update V with v up instead of git pull

cmd/tools/fast/fast.v

@@ -15,9 +15,9 @@ fn main() {
 	println('fast.html generator\n')
 	// Fetch the last commit's hash
 	println('Fetching updates...')
-	ret := os.system('git pull --rebase')
+	ret := os.system('$vdir/v up')
 	if ret != 0 {
-		println('failed to git pull')
+		println('failed to update V')
 		return
 	}
 	mut commit_hash := exec('git rev-parse HEAD')

vlib/v/gen/fn.v

@@ -636,9 +636,10 @@ fn (mut g Gen) call_args(args []ast.CallArg, expected_types []table.Type) {
 				g.expr(arg.expr)
 			} else if use_tmp_var_autofree {
 				for name in g.tmp_arg_vars_to_free {
-					// Save expressions in temp variables so that they can be freed later.
+					// We saved expressions in temp variables so that they can be freed later.
 					// `foo(str + str2) => x := str + str2; foo(x); x.free()`
 					// g.write('_arg_expr_${g.called_fn_name}_$i')
+					// Use these variables here.
 					if name.contains('_$i') {
 						g.write(name)
 					}