tests/test-gendoc-da.t

perf: add a `--clear-caches` to `perfbranchmapupdate`

This flag will help to measure the time we spend loading various cache that
support the branchmap update.

Example for an 500 000 revisions repository:

hg perfbranchmapupdate --base 'not tip' --target 'tip'
! wall 0.000860 comb 0.000000 user 0.000000 sys 0.000000 (best of 336)
hg perfbranchmapupdate --base 'not tip' --target 'tip' --clear-caches
! wall 0.029494 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)

#require docutils gettext

  $ $TESTDIR/check-gendoc da
  checking for parse errors