Merge branch 'ab/wildmatch-tests'

Merge branch 'ab/wildmatch-tests'

More tests for wildmatch functions.

* ab/wildmatch-tests:
  wildmatch test: mark test as EXPENSIVE_ON_WINDOWS
  test-lib: add an EXPENSIVE_ON_WINDOWS prerequisite
  wildmatch test: create & test files on disk in addition to in-memory
  wildmatch test: perform all tests under all wildmatch() modes
  wildmatch test: use test_must_fail, not ! for test-wildmatch
  wildmatch test: remove dead fnmatch() test code
  wildmatch test: use a paranoia pattern from nul_match()
  wildmatch test: don't try to vertically align our output
  wildmatch test: use more standard shell style
  wildmatch test: indent with tabs, not spaces