merge revision(s) r45646: [Backport #9765]

	* ext/stringio/stringio.c (strio_putc): fix for non-ascii
	  encoding, like as IO#putc.  [ruby-dev:48114] [Bug #9765]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@46213 b2dd03c8-39d4-4d8f-98ff-823fe69b080e