merge revision(s) r47196: [Backport #10144]

	* time.c (time_timespec): fix tv_nsec overflow
	  [Bug #10144]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@47482 b2dd03c8-39d4-4d8f-98ff-823fe69b080e