remove docs about delegating to special methods; it does no such thing

Doc/library/math.rst

@@ -57,9 +57,6 @@ Number-theoretic and representation functions
    Return the floor of *x* as a float, the largest integer value less than or equal
    to *x*.
 
-   .. versionchanged:: 2.6
-      Added :meth:`__floor__` delegation.
-
 
 .. function:: fmod(x, y)
 
@@ -137,7 +134,7 @@ Number-theoretic and representation functions
 .. function:: trunc(x)
 
    Return the :class:`Real` value *x* truncated to an :class:`Integral` (usually
-   a long integer). Delegates to ``x.__trunc__()``.
+   a long integer).
 
    .. versionadded:: 2.6