merge revision(s) 42542: [Backport #8910]

	* random.c (rb_random_ulong_limited): coerce before check negative.
	  [Fixes GH-379]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@43079 b2dd03c8-39d4-4d8f-98ff-823fe69b080e