More optimizations for the single-file merge case.
More optimizations for the single-file merge case.

* subversion/libsvn_client/merge.c
  (remove_noop_merge_ranges): Avoid a linear trampse through the array
    of operative revisions if the entire range fails to overlap with the
    requested merge range.

Suggested by: kfogel

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@872022 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion