Merge branch 'jh/fsmonitor-icase-corner-case-fix'

Merge branch 'jh/fsmonitor-icase-corner-case-fix'

FSMonitor client code was confused when FSEvents were given in a
different case on a case-insensitive filesystem, which has been
corrected.

Acked-by: Patrick Steinhardt <ps@pks.im>
cf. <ZehofMaSZyUq8S1N@tanuki>

* jh/fsmonitor-icase-corner-case-fix:
  fsmonitor: support case-insensitive events
  fsmonitor: refactor bit invalidation in refresh callback
  fsmonitor: trace the new invalidated cache-entry count
  fsmonitor: return invalidated cache-entry count on non-directory event
  fsmonitor: remove custom loop from non-directory path handler
  fsmonitor: return invalidated cache-entry count on directory event
  fsmonitor: move untracked-cache invalidation into helper functions
  fsmonitor: refactor untracked-cache invalidation
  dir: create untracked_cache_invalidate_trimmed_path()
  fsmonitor: refactor refresh callback for non-directory events
  fsmonitor: clarify handling of directory events in callback helper
  fsmonitor: refactor refresh callback on directory events
  t7527: add case-insensitve test for FSMonitor
  name-hash: add index_dir_find()