Permit calls to builtins and intrinsics in kernels loops.

Permit calls to builtins and intrinsics in kernels loops.

This tweak to the OpenACC kernels loop annotation relaxes the
restrictions on function calls in the loop body.  Normally calls to
functions not explicitly marked with a parallelism attribute are not
permitted, but C/C++ builtins and Fortran intrinsics have known
semantics so we can generally permit those without restriction.  If
any turn out to be problematical, we can add on here to recognize
them, or in the processing of the "auto" annotations.

2020-08-22  Sandra Loosemore  <sandra@codesourcery.com>

	gcc/c-family/
	* c-omp.cc (annotate_loops_in_kernels_regions): Test for
	calls to builtins.

	gcc/fortran/
	* openmp.cc (check_expr_for_invalid_calls): Check for intrinsic
	functions.

	gcc/testsuite/
	* c-c++-common/goacc/kernels-loop-annotation-20.c: New.
	* gfortran.dg/goacc/kernels-loop-annotation-20.f95: New.