Update NEWS and documents [ci skip]

[Feature #11297] [Feature #16123]

NEWS

@@ -77,6 +77,9 @@ sufficient information, see the ChangeLog file or Redmine
       # .bar
       .baz # => foo.baz
 
+* Calling a private method with a literal <code>self.</code> as the receiver
+  is now allowed. [Feature #11297] [Feature #16123]
+
 === Core classes updates (outstanding ones only)
 
 Complex::

doc/syntax/assignment.rdoc

@@ -93,7 +93,8 @@ be cached.  To call the method, use <code>self.big_calculation</code>.
 
 You can force a method call by using empty argument parentheses as shown above
 or by using an explicit receiver like <code>self.</code>.  Using an explicit
-receiver may raise a NameError if the method's visibility is not public.
+receiver may raise a NameError if the method's visibility is not public or the
+receiver is the literal <code>self</code>.
 
 Another commonly confusing case is when using a modifier +if+:
 

doc/syntax/modules_and_classes.rdoc

@@ -191,8 +191,8 @@ Here is an example:
   a.n b # raises NoMethodError A is not a subclass of B
 
 The third visibility is +private+.  A private method may not be called with a
-receiver, not even +self+.  If a private method is called with a receiver a
-NoMethodError will be raised.
+receiver, not even if it equals +self+.  If a private method is called with a
+receiver other than a literal +self+ a NoMethodError will be raised.
 
 === +alias+ and +undef+