Add shootout meteor contest benchmark.

This implementation of the meteor contest implements:
 - insertion check with bit trick;
 - pregenetation of every feasible placement of the pieces on the
   board;
 - filtering of placement that implies unfeasible board
 - central symetry breaking
remove useless Iterate impl, and permute the order of the argument of iterate

Writing iterate(x, f) is more logical as rust iterator pipeline is left to right.
Improve variable naming.
remove `cast::unsafe_copy`

This is the same functionality as `ptr::read_ptr`.
auto merge of #10497 : thestinger/rust/cleanup, r=cmr

This is the same functionality as `ptr::read_ptr`.
auto merge of #10478 : TeXitoi/rust/shootout-meteor, r=brson

This implementation of the meteor contest implements:
 - insertion check with bit trick;
 - pregenetation of every feasible placement of the pieces on the
   board;
 - filtering of placement that implies unfeasible board
 - central symetry breaking

related to #2776