merge revision(s) 45287:45290: [Backport #9600]

	* process.c (obj2uid, obj2gid): now getpwnam_r() and getgrnam_r()
	  may need larger buffers than sysconf values, so retry with
	  expanding the buffer when ERANGE is returned.
	  [ruby-core:61325] [Bug #9600]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@46511 b2dd03c8-39d4-4d8f-98ff-823fe69b080e