libcaf.h: Add parameter stat to caf_get() and caf_send()'s function prototypes.

libgfortran/ChangeLog:

2016-07-22  Andre Vehreschild  <vehre@gcc.gnu.org>

	* caf/libcaf.h: Add parameter stat to caf_get() and
	caf_send()'s function prototypes.
	* caf/single.c (_gfortran_caf_get): Implement reporting
	error using stat instead of abort().
	(_gfortran_caf_send): Same.
	(_gfortran_caf_sendget): Use NULL for stat when calling
	caf_send().


gcc/testsuite/ChangeLog:

2016-07-22  Andre Vehreschild  <vehre@gcc.gnu.org>

	* gfortran.dg/coarray_stat_2.f90: New test.

From-SVN: r238636