Add support for the mixed type

Zend/tests/type_declarations/mixed/casting/mixed_cast_error.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Test that a mixed casting is not supported
+--FILE--
+<?php
+
+$foo = (mixed) 12;
+
+?>
+--EXPECTF--
+Parse error: syntax error, unexpected '12' (T_LNUMBER) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_error1.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a mixed parameter type can't be overridden by a built-in type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(mixed $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(bool $a) {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of Bar::method(bool $a) must be compatible with Foo::method(mixed $a) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_error2.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a mixed parameter type can't be overridden by a nullable built-in type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(mixed $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(?int $a) {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of Bar::method(?int $a) must be compatible with Foo::method(mixed $a) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_error3.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a mixed parameter type can't be overridden by a union of all built-in types
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(mixed $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(bool|int|float|string|array|object|null $a) {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of Bar::method(object|array|string|int|float|bool|null $a) must be compatible with Foo::method(mixed $a) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_error4.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a mixed parameter type can't be overridden by a union type of classes
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(mixed $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(stdClass|Foo $a) {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of Bar::method(stdClass|Foo $a) must be compatible with Foo::method(mixed $a) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_success1.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a mixed parameter type supports invariance
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(mixed $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(mixed $a) {}
+}
+
+?>
+--EXPECT--

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_success2.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a mixed parameter type can be overridden by no type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(mixed $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method($a) {}
+}
+
+?>
+--EXPECT--

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_success3.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a parameter of no type can be overridden by the mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method($a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(mixed $a) {}
+}
+
+?>
+--EXPECT--

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_success4.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a parameter of a built-in type can be overridden by the mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(int $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(mixed $a) {}
+}
+
+?>
+--EXPECT--

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_success5.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a parameter of a nullable built-in type can be overridden by the mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(?int $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(mixed $a) {}
+}
+
+?>
+--EXPECT--

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_success6.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a parameter of a union of all built-in types can be overridden by the mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(bool|int|float|string|array|object|null $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(mixed $a) {}
+}
+
+?>
+--EXPECT--

Zend/tests/type_declarations/mixed/inheritance/mixed_parameter_inheritance_success7.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a parameter of a union type of classes can be overridden by the mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public function method(stdClass|Foo $a) {}
+}
+
+class Bar extends Foo
+{
+    public function method(mixed $a) {}
+}
+
+?>
+--EXPECT--

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error1.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a property of mixed type can't be overridden by a property of a built-in type
+--FILE--
+<?php
+
+class Foo
+{
+    public mixed $property1;
+}
+
+class Bar extends Foo
+{
+    public int $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must be mixed (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error2.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a property of mixed type can't be overridden by a property of class type
+--FILE--
+<?php
+
+class Foo
+{
+    public mixed $property1;
+}
+
+class Bar extends Foo
+{
+    public stdClass $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must be mixed (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error3.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a property of mixed type can't be overridden by an untyped property
+--FILE--
+<?php
+
+class Foo
+{
+    public mixed $property1;
+}
+
+class Bar extends Foo
+{
+    public $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must be mixed (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error4.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a property of mixed type can't be overridden by a property of a union type
+--FILE--
+<?php
+
+class Foo
+{
+    public mixed $property1;
+}
+
+class Bar extends Foo
+{
+    public bool|int|float|string|array|object|null $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must be mixed (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error5.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a property of a built-in type can't be overridden by a property of mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public int $property1;
+}
+
+class Bar extends Foo
+{
+    public mixed $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must be int (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error6.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a property of class type can't be overridden by a property of mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public stdClass $property1;
+}
+
+class Bar extends Foo
+{
+    public mixed $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must be stdClass (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error7.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that an untyped property can't be overridden by a property of mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public $property1;
+}
+
+class Bar extends Foo
+{
+    public mixed $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must not be defined (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_error8.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Test that a property of a union type can't be overridden by a property of mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public bool|int|float|string|array|object|null $property1;
+}
+
+class Bar extends Foo
+{
+    public mixed $property1;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Bar::$property1 must be object|array|string|int|float|bool|null (as in class Foo) in %s on line %d

Zend/tests/type_declarations/mixed/inheritance/mixed_property_inheritance_success.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Test that a property of mixed property type can be overridden by a property of mixed type
+--FILE--
+<?php
+
+class Foo
+{
+    public mixed $property1;
+}
+
+class Bar extends Foo
+{
+    public mixed $property1;
+}
+
+?>
+--EXPECT--