tests/check-gendoc

revsetlang: build optimized tree by helper function

This should make optimize() more readable, but it doubles the parsing cost.

  (original)
  $ python -m timeit -n10000 -s 'from mercurial import revsetlang as L' \
  'L.optimize(L.analyze(L.parse("::tip")))'
  10000 loops, best of 3: 18.1 usec per loop

  (this patch)
  $ python -m timeit -n10000 -s 'from mercurial import revsetlang as L' \
  'L._treecache.clear(); L.optimize(L.analyze(L.parse("::tip")))'
  10000 loops, best of 3: 48.4 usec per loop

30usec isn't dominant compared to the revset evaluation, but that is a cost.
That's why a parsed tree is cached, which can benefit in hgweb or chg server.

#!/bin/sh
HGENCODING=UTF-8
export HGENCODING

echo ".. -*- coding: utf-8 -*-" > gendoc.txt
echo "" >> gendoc.txt
LANGUAGE=$1 python "$TESTDIR/../doc/gendoc.py" >> gendoc.txt 2> /dev/null || exit

echo "checking for parse errors"
python "$TESTDIR/../doc/docchecker" gendoc.txt
python "$TESTDIR/../doc/runrst" html gendoc.txt /dev/null