Add test describing overloading behaviour

Author: Girgias

Zend/tests/type_declarations/literal_types/false_no_coercion_on_overload.phpt

@@ -0,0 +1,31 @@
+--TEST--
+No coercion should be applied to type false even if it's an overloading
+--FILE--
+<?php
+
+class P {
+    public function foo($v): array|bool {
+        return $v;
+    }
+}
+
+class C {
+    public function foo($v): array|false {
+        return $v;
+    }
+}
+
+$p = new P();
+$c = new C();
+
+var_dump($p->foo(0));
+try {
+    var_dump($c->foo(0));
+} catch (\TypeError $e) {
+    echo $e->getMessage(), \PHP_EOL;
+}
+
+?>
+--EXPECT--
+bool(false)
+C::foo(): Return value must be of type array|false, int returned

Zend/tests/type_declarations/literal_types/true_no_coercion_on_overload.phpt

@@ -0,0 +1,31 @@
+--TEST--
+No coercion should be applied to type true even if it's an overloading
+--FILE--
+<?php
+
+class P {
+    public function foo($v): array|bool {
+        return $v;
+    }
+}
+
+class C {
+    public function foo($v): array|true {
+        return $v;
+    }
+}
+
+$p = new P();
+$c = new C();
+
+var_dump($p->foo(1));
+try {
+    var_dump($c->foo(1));
+} catch (\TypeError $e) {
+    echo $e->getMessage(), \PHP_EOL;
+}
+
+?>
+--EXPECT--
+bool(true)
+C::foo(): Return value must be of type array|true, int returned