insns.def (opt_succ): remove Time#succ optimization

Time#succ is a deprecated method and not frequently used, so this wastes
icache in vm_exec_core.  Using bloat-o-meter in the Linux kernel source
to shows a small reduction on my x86-64 system:

$ ~/linux/scripts/bloat-o-meter ruby.before ruby.after
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-57 (-57)
function                                     old     new   delta
vm_exec_core                               24216   24159     -57

[Feature #10501]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48415 b2dd03c8-39d4-4d8f-98ff-823fe69b080e