[ruby-cvs:78995] e5c441a4a2 (master): Optimize Array#rotate!(n) for n = 1 and n = -1

Ary Borenszweig	2019-11-30 05:59:47 +0900 (Sat, 30 Nov 2019)

  New Revision: e5c441a4a2

  https://github.com/ruby/ruby/commit/e5c441a4a2

  Log:
    Optimize Array#rotate!(n) for n = 1 and n = -1
    
    For the most common cases of `rotate!` one place to the right or to the
    left, instead of doing some reversals of the array we just keep a single
    value in a temporary value, use memmove and then put the temporary
    value where it should be.

  Modified files:
    array.c