Tests: Add BackedEnum::values() test suite for enums

Zend/tests/enum/backed-values-empty.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Backed enums: values() on empty enum returns []
+--FILE--
+<?php
+
+enum A: string {}
+
+var_dump(A::values());
+
+?>
+--EXPECT--
+array(0) {
+}
+

Zend/tests/enum/backed-values-ignore-regular-consts.phpt

@@ -0,0 +1,20 @@
+--TEST--
+BackedEnum::values() only returns case values, not regular constants
+--FILE--
+<?php
+enum Mixed_: string {
+    case A = 'a';
+    case B = 'b';
+
+    public const REGULAR_CONST = 'not_a_case';
+}
+var_dump(Mixed_::values());
+?>
+--EXPECT--
+array(2) {
+  [0]=>
+  string(1) "a"
+  [1]=>
+  string(1) "b"
+}
+

Zend/tests/enum/backed-values-int.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Backed enums: values() returns ints
+--FILE--
+<?php
+
+enum Priority: int {
+    case Low = 1;
+    case Medium = 5;
+    case High = 10;
+}
+
+var_dump(Priority::values());
+
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  int(1)
+  [1]=>
+  int(5)
+  [2]=>
+  int(10)
+}
+

Zend/tests/enum/backed-values-not-on-pure.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Unit enums do not have values()
+--FILE--
+<?php
+
+enum U {
+    case A;
+}
+
+var_dump(method_exists(U::class, 'values'));
+
+?>
+--EXPECT--
+bool(false)
+

Zend/tests/enum/backed-values-order.phpt

@@ -0,0 +1,21 @@
+--TEST--
+BackedEnum::values() preserves declaration order
+--FILE--
+<?php
+enum Order: int {
+    case Third = 3;
+    case First = 1;
+    case Second = 2;
+}
+var_dump(Order::values());
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  int(3)
+  [1]=>
+  int(1)
+  [2]=>
+  int(2)
+}
+

Zend/tests/enum/backed-values-string.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Backed enums: values() returns strings
+--FILE--
+<?php
+
+enum Color: string {
+    case Red = 'red';
+    case Green = 'green';
+    case Blue = 'blue';
+}
+
+var_dump(Color::values());
+
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  string(3) "red"
+  [1]=>
+  string(5) "green"
+  [2]=>
+  string(4) "blue"
+}
+