Support methods prefixed with underscore

Fixes phpspec#108

While it was a common convention to prefix "private" methods with an underscore
in earlier version of php, with support for method visibility this is no longer
common.

Additionally there are a number of exception such as the Soap library where
this convention did not hold and code was not mockable.

src/Prophecy/Doubler/Generator/ClassMirror.php

@@ -31,16 +31,6 @@
  */
 class ClassMirror
 {
-    private static $reflectableMethods = array(
-        '__construct',
-        '__destruct',
-        '__sleep',
-        '__wakeup',
-        '__toString',
-        '__call',
-        '__invoke'
-    );
-
     /**
      * Reflects provided arguments into class node.
      *
@@ -109,11 +99,6 @@ private function reflectClassToNode(ReflectionClass $class, Node\ClassNode $node
         }
 
         foreach ($class->getMethods(ReflectionMethod::IS_PUBLIC) as $method) {
-            if (0 === strpos($method->getName(), '_')
-                && !in_array($method->getName(), self::$reflectableMethods)) {
-                continue;
-            }
-
             if (true === $method->isFinal()) {
                 $node->addUnextendableMethod($method->getName());
                 continue;

tests/Doubler/Generator/ClassMirrorTest.php

@@ -307,18 +307,18 @@ public function it_reflects_all_interfaces_methods()
     /**
      * @test
      */
-    public function it_ignores_virtually_private_methods()
+    public function it_does_not_ignores_virtually_private_methods()
     {
         $class = new \ReflectionClass('Fixtures\Prophecy\WithVirtuallyPrivateMethod');
 
         $mirror = new ClassMirror();
 
         $classNode = $mirror->reflect($class, array());
 
-        $this->assertCount(2, $classNode->getMethods());
+        $this->assertCount(3, $classNode->getMethods());
         $this->assertTrue($classNode->hasMethod('isAbstract'));
         $this->assertTrue($classNode->hasMethod('__toString'));
-        $this->assertFalse($classNode->hasMethod('_getName'));
+        $this->assertTrue($classNode->hasMethod('_getName'));
     }
 
     /**
@@ -614,7 +614,7 @@ public function it_can_not_double_an_enum()
         }
 
         $this->expectException(ClassMirrorException::class);
-  
+
         $classNode = (new ClassMirror())->reflect(new \ReflectionClass('Fixtures\Prophecy\Enum'), []);
     }