For easier maintenance.

	gcc/testsuite/
	* gfortran.dg/goacc/assumed.f95: Use relative line numbers for a
	few DejaGnu directives.
	* gfortran.dg/goacc/list.f95: Likewise.
	* gfortran.dg/goacc/loop-1-2.f95: Likewise.
	* gfortran.dg/goacc/loop-1.f95: Likewise.
	* gfortran.dg/goacc/reduction.f95: Likewise.