[issue13780] make YieldFrom its own node

[Terry J. Reedy]

Changes by Terry J. Reedy <tjreedy at udel.edu>:


----------
components: +Interpreter Core
stage:  -> patch review
type:  -> enhancement
versions: +Python 3.3

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue13780>
_______________________________________