Add additional test coverage

Author: nikic

Diff for: Zend/tests/first_class_callable_dynamic.phpt

@@ -0,0 +1,53 @@
+--TEST--
+Acquire callable through various dynamic constructs
+--FILE--
+<?php
+
+class A {
+    public static function b($x) {
+        return $x;
+    }
+
+    public function c($x) {
+        return $x;
+    }
+}
+
+$name = 'strlen';
+$fn = $name(...);
+var_dump($fn('x'));
+
+$name = ['A', 'b'];
+$fn = $name(...);
+var_dump($fn(2));
+
+$name = [new A, 'c'];
+$fn = $name(...);
+var_dump($fn(3));
+
+$name1 = 'A';
+$name2 = 'b';
+$fn = $name1::$name2(...);
+var_dump($fn(4));
+
+$name2 = 'c';
+$fn = (new A)->$name2(...);
+var_dump($fn(5));
+
+$fn = [A::class, 'b'](...);
+var_dump($fn(6));
+
+$o = new stdClass;
+$o->prop = A::b(...);
+($o->prop)(7);
+
+$nam
+
+?>
+--EXPECT--
+int(1)
+int(2)
+int(3)
+int(4)
+int(5)
+int(6)

Diff for: Zend/tests/first_class_callable_errors.phpt

@@ -0,0 +1,57 @@
+--TEST--
+Trying to acquire callable to something that's not callable
+--FILE--
+<?php
+
+class Test {
+    private static function privateMethod() {}
+
+    public function instanceMethod() {}
+}
+
+try {
+    $fn = 123;
+    $fn(...);
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    does_not_exist(...);
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    stdClass::doesNotExist(...);
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    (new stdClass)->doesNotExist(...);
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    [new stdClass, 'doesNotExist'](...);
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    Test::privateMethod(...);
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    Test::instanceMethod(...);
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+Value of type int is not callable
+Call to undefined function does_not_exist()
+Call to undefined method stdClass::doesNotExist()
+Call to undefined method stdClass::doesNotExist()
+Call to undefined method stdClass::doesNotExist()
+Call to private method Test::privateMethod() from global scope
+Non-static method Test::instanceMethod() cannot be called statically

Diff for: Zend/tests/first_class_callable_refs.phpt

@@ -0,0 +1,18 @@
+--TEST--
+First class callables and references
+--FILE--
+<?php
+
+function &id(&$x) {
+    return $x;
+}
+
+$fn = id(...);
+$i = 0;
+$i2 =& $fn($i);
+$i++;
+var_dump($i2);
+
+?>
+--EXPECT--
+int(1)

Diff for: Zend/tests/first_class_callable_signature.phpt

@@ -0,0 +1,20 @@
+--TEST--
+First class callables should retain the signature for reflection
+--FILE--
+<?php
+
+function test(int $a, string &$b, Foo... $c) {}
+
+echo new ReflectionFunction(test(...));
+
+?>
+--EXPECTF--
+Closure [ <user> function test ] {
+  @@ %s 3 - 3
+
+  - Parameters [3] {
+    Parameter #0 [ <required> int $a ]
+    Parameter #1 [ <required> string &$b ]
+    Parameter #2 [ <optional> Foo ...$c ]
+  }
+}