insns.def: adjust index type
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56911 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
insns.def: adjust index type
get rid of (potential) overflow.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56911 b2dd03c8-39d4-4d8f-98ff-823fe69b080e