re PR bootstrap/89864 (gcc fails to build/bootstrap with XCode 10.2)

fix PR89864

      2019-04-18  Erik Schnetter  <schnetter@gmail.com>
	  Jakub Jelinek  <jakub@redhat.com>
	  Iain Sandoe  <iain@sandoe.co.uk>

	PR bootstrap/89864
	* inclhack.def (darwin_ucred__Atomic): New, work around _Atomic keyword
	use in headers included by C++.
	* fixincl.x: Regenerated.


Co-Authored-By: Iain Sandoe <iain@sandoe.co.uk>
Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r270435