Simplify the proposal for gen.throw().

pep-0288.txt

@@ -119,17 +119,12 @@ Specification for Generator Exception Passing:
     genraise(), raiseinto(), and flush().  None of these fit as well
     as throw().
 
-    Note B: The full throw() syntax should exactly match raise's syntax:
+    Note B:  To keep the throw() syntax simple only the instance
+    version of the raise syntax would be supported (no variants for
+    "raise string" or "raise class, instance").
 
-        throw([expression, [expression, [expression]]])
-
-    Accordingly, it should be implemented to handle all of the following:
-
-        raise string                    g.throw(string)
-        raise string, data              g.throw(string,data)
-        raise class, instance           g.throw(class,instance)
-        raise instance                  g.throw(instance)
-        raise                           g.throw()
+    Calling "g.throw(instance)" would correspond to writing
+    "raise instance" immediately after the most recent yield.