* insns.def (newhashfromarray): added to replace `core_hash_from_ary`
  method to eliminate method call overhead.

  On my environment, I got the following benchmark results:

  x = {x: 1}

                    modified:   7864988.6 i/s
                       trunk:   6004098.1 i/s - 1.31x  slower


  x = {x: 1, y: 2}

                       trunk:   6127338.4 i/s
                    modified:   5232380.0 i/s - 1.17x  slower


  x = {x: 1, y: 2, z: 3}

                    modified:   6089553.1 i/s
                       trunk:   5249333.5 i/s - 1.16x  slower

  This trivial improvement should be reconsider because of usage of
  this instruction.

* compile.c: ditto.

* defs/id.def, vm.c: remove unused functions.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65343 b2dd03c8-39d4-4d8f-98ff-823fe69b080e