ruby: integer overflow in rb_ary_splice/update/replace() - beg + rlen

Integer overflow in the 1 rbarysplice function in Ruby 1.8.4 and earlier, 1.8.5 before 1.8.5-p231, 1.8.6 before 1.8.6-p230, 1.8.7 before 1.8.7-p22, and 1.9.0 before 1.9.0-2; and 2 the rbaryreplace function in 1.6.x allows context-dependent attackers to trigger memory corruption, aka the "beg +...