tests/test-fuzz-targets.t

status: intersect matcher with narrow matcher instead of filtering afterwards

I seem to have done a very naive move of the code from the narrow
extension into core in e411774a2e0f (narrow: move status-filtering to
core and to ctx, 2018-08-02). It seems obvious that a better way is to
intersect the matchers.

Note that this means that when requesting status for the working
directory in a narrow repo, we now pass the narrow matcher (possibly
intersected with a user-provided matcher) into _buildstatus() and then
into dirstate.status() and dirstate.walk(), which will the intersect
it again with the narrow matcher. That's functionally fine, but
wasteful. I hope to later remove the dirstate wrapping that adds the
second layer of matcher intersection.

Differential Revision: https://phab.mercurial-scm.org/D4897

#require test-repo

  $ cd $TESTDIR/../contrib/fuzz

#if clang-libfuzzer
  $ make -s clean all
#endif
#if no-clang-libfuzzer clang-6.0
  $ make -s clean all CC=clang-6.0 CXX=clang++-6.0
#endif
#if no-clang-libfuzzer no-clang-6.0
  $ exit 80
#endif

Just run the fuzzers for five seconds each to verify it works at all.
  $ ./bdiff -max_total_time 5
  $ ./mpatch -max_total_time 5
  $ ./xdiff -max_total_time 5