maple_tree: add mas_prev_range() and mas_find_range_rev interface

Some users of the maple tree may want to move to the previous range
regardless of the value stored there.  Add this interface as well as the
'find' variant to support walking to the first value, then iterating over
the previous ranges.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Liam R. Howlett <[email protected]>
Cc: Vernon Yang <[email protected]>
Cc: David Binderman <[email protected]>
Cc: Peng Zhang <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions