Ruby

string.c: improve String#scan

• string.c (rb_str_rstrip_bang): improve the performance in 50%
  for a string pattern, and in 10% for a regexp pattern. get rid
  of making MatchData in middle, which is not used.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59496 b2dd03c8-39d4-4d8f-98ff-823fe69b080e