merge revision(s) r46243,r46244: [Backport #9882] [Backport #9883]

	* string.c (rb_str_substr): need to reset code range for shared
	  string too, not only copied string.
	  [ruby-core:62842] [Bug #9882]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@46599 b2dd03c8-39d4-4d8f-98ff-823fe69b080e