checker: fix error for cast to u8 (#13058)

vlib/v/checker/checker.v

@@ -2669,7 +2669,7 @@ pub fn (mut c Checker) cast_expr(mut node ast.CastExpr) ast.Type {
 		}
 	} else if mut to_sym.info is ast.Alias {
 		if !c.check_types(from_type, to_sym.info.parent_type) && !(final_to_sym.is_int()
-			&& final_from_sym.kind == .enum_) {
+			&& final_from_sym.kind in [.enum_, .bool]) {
 			c.error('cannot convert type `$from_sym.name` to `$to_sym.name` (alias to `$final_to_sym.name`)',
 				node.pos)
 		}

vlib/v/tests/cast_to_u8_test.v

@@ -0,0 +1,16 @@
+module main
+
+fn test_cast_to_alias() {
+	r1 := u8(byte(1))
+	println(r1)
+	assert '$r1' == '1'
+
+
+	r2 := u8(byte(true))
+	println(r2)
+	assert '$r2' == '1'
+
+	r3 := u8(true)
+	println(r3)
+	assert '$r3' == '1'
+}