to be valid.
* string.c (enc_strlen): coderange specified version of
rb_enc_strlen(). use rb_enc_fast_mbclen() if coderange is 7bit
or valid.
* string.c (str_gsub): use rb_enc_fast_mbclen().
* string.c (rb_str_reverse, rb_str_split_m, rb_str_each_char,
scan_once): ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@23495 b2dd03c8-39d4-4d8f-98ff-823fe69b080e