That's the C runtime starting up and finishing. That amount of overhead is incurred by (nearly) any program; in fact, worse overhead is incurred using the Sun method of having an empty file, because you have to run the more complex /bin/sh (or equivalent) instead of just a trivial compiled program.

ltrace gives a better view of what the program itself (as opposed to the runtime) is doing.

This is GNU's Appropriate Legal Notices as required by section 5d of the GPLv3:

  An interactive user interface displays "Appropriate Legal Notices"
  to the extent that it includes a convenient and prominently visible
  feature that (1) displays an appropriate copyright notice, and (2)
  tells the user that there is no warranty for the work (except to the
  extent that warranties are provided), that licensees may convey the
  work under this License, and how to view a copy of this License.  If
  the interface presents a list of user commands or options, such as a
  menu, a prominent item in the list meets this criterion.

Indeed: http://git.savannah.gnu.org/cgit/coreutils.git/tree/src/true...

That's pretty clearly a non-trivial source file. Obviously a pointless one, but copyrightable. And it has the standard GNU copyleft blurb at the top.