[docs] SyntaxError in asdl when building 2.7 with system Python 3 (issue 15964)

[ezio.melotti at gmail.com]

http://bugs.python.org/review/15964/diff/7830/Parser/spark.py
File Parser/spark.py (right):

http://bugs.python.org/review/15964/diff/7830/Parser/spark.py#newcode833
Parser/spark.py:833: s = '\t\t %s ::= ' % str(lhs)
The str() here is no longer necessary, since %s should call it already.

http://bugs.python.org/review/15964/diff/7830/Parser/spark.py#newcode834
Parser/spark.py:834: s += ' '.join(rhs[:pos]) + ' '
The trailing space here is no longer necessary, since it has been moved
on the next line.

http://bugs.python.org/review/15964/