gen: fix `arr.last().field` (#7076)

vlib/builtin/array_test.v

@@ -1002,6 +1002,27 @@ fn test_array_string_pop() {
 	assert a.cap == 3
 }
 
+fn test_array_first() {
+	a := [3]
+	assert a.first() == 3
+	b := [1, 2, 3, 4]
+	assert b.first() == 1
+	c := ['abc', 'def']
+	assert c.first()[0] == `a`
+	s := [Chunk{'a'}]
+	assert s.first().val == 'a'
+}
+
+fn test_array_last() {
+	a := [3]
+	assert a.last() == 3
+	b := [1, 2, 3, 4]
+	assert b.last() == 4
+	c := ['abc', 'def']
+	assert c.last()[0] == `d`
+	s := [Chunk{'a'}]
+	assert s.last().val == 'a'
+}
 
 [direct_array_access]
 fn test_direct_array_access() {

vlib/v/gen/fn.v

@@ -365,6 +365,7 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 	if node.name == 'str' {
 		g.gen_str_for_type(node.receiver_type)
 	}
+	mut has_cast := false
 	// TODO performance, detect `array` method differently
 	if left_sym.kind == .array && node.name in
 		['repeat', 'sort_with_compare', 'free', 'push_many', 'trim', 'first', 'last', 'pop', 'clone', 'reverse', 'slice'] {
@@ -374,7 +375,8 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 		receiver_type_name = 'array'
 		if node.name in ['last', 'first', 'pop'] {
 			return_type_str := g.typ(node.return_type)
-			g.write('*($return_type_str*)')
+			has_cast = true
+			g.write('(*($return_type_str*)')
 		}
 	}
 	mut name := util.no_dots('${receiver_type_name}_$node.name')
@@ -428,6 +430,9 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 	} else {
 		g.expr(node.left)
 	}
+	if has_cast {
+		g.write(')')
+	}
 	is_variadic := node.expected_arg_types.len > 0 && node.expected_arg_types[node.expected_arg_types.len -
 		1].has_flag(.variadic)
 	if node.args.len > 0 || is_variadic {