cgen: fix zero init bug of embedded structs (#7567)

vlib/v/gen/cgen.v

@@ -4460,6 +4460,9 @@ fn (mut g Gen) struct_init(struct_init ast.StructInit) {
 				// TODO handle/require optionals in inits
 				continue
 			}
+			if field.typ in info.embeds {
+				continue
+			}
 			g.zero_struct_field(field)
 			if is_multiline {
 				g.writeln(',')

vlib/v/tests/struct_embed_test.v

@@ -26,6 +26,11 @@ fn test_default_value() {
 	b := Bar{Foo: Foo{}}
 	assert b.y == 5
 }
+
+fn test_default_value_without_init() {
+	b := Bar{}
+	assert b.y == 5
+}
 /* TODO
 fn test_initialize() {
 	b := Bar{x: 1, y: 2}