Improve the error message that is printed when a memory allocation
fails, by including the location, and the size of the allocation that
failed.

Regtested on x86_64-pc-linux-gnu.

gcc/fortran/ChangeLog:

2019-08-17  Janne Blomqvist  <jb@gcc.gnu.org>

	PR fortran/68401
	* trans-decl.c (gfc_build_builtin_function_decls): Replace
	os_error with os_error_at decl.
	* trans.c (trans_runtime_error_vararg): Modify so the error
	function decl is passed directly.
	(gfc_trans_runtime_error): Pass correct error function decl.
	(gfc_trans_runtime_check): Likewise.
	(trans_os_error_at): New function.
	(gfc_call_malloc): Use trans_os_error_at.
	(gfc_allocate_using_malloc): Likewise.
	(gfc_call_realloc): Likewise.
	* trans.h (gfor_fndecl_os_error): Replace with gfor_fndecl_os_error_at.

libgfortran/ChangeLog:

2019-08-17  Janne Blomqvist  <jb@gcc.gnu.org>

	PR fortran/68401
	* gfortran.map: Add GFORTRAN_10 node, add _gfortran_os_error_at
	symbol.
	* libgfortran.h (os_error_at): New prototype.
	* runtime/error.c (os_error_at): New function.

From-SVN: r274599