string.c: term fill

* string.c (rb_str_chomp_bang): fill wchar terminator.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48760 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
string.c: term fill

* string.c (rb_str_chop_bang): fill wchar terminator.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48761 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
string.c: term fill

* string.c (rb_str_splice_0): fill wchar terminator.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48762 b2dd03c8-39d4-4d8f-98ff-823fe69b080e