PR 78534, 84509 Fix libgfortran API for PAUSE statement

PR 78534, 84509 Fix libgfortran API for PAUSE statement

This patch changes the libgfortran API for the PAUSE statement. By
passing a GFC_INTEGER_8 it handles -fdefault-integer-8, and for the
character version passing the length as a size_t.

Regtested on x86_64-pc-linux-gnu, committed as obvious.

gcc/fortran/ChangeLog:

2018-02-22  Janne Blomqvist  <jb@gcc.gnu.org>

	PR 78534
	PR 84509
	* trans-decl.c (gfc_build_builtin_function_decls): Pass
	gfc_int8_type node to pause_numeric, size_type_node to
	pause_string.
	* trans-stmt.c (gfc_trans_pause): Likewise.

libgfortran/ChangeLog:

2018-02-22  Janne Blomqvist  <jb@gcc.gnu.org>

	PR 78534
	PR 84509
	* runtime/pause.c (pause_numeric): Modify to take GFC_INTEGER_8
	argument.
	(pause_string): Modify to take size_t character length argument.

From-SVN: r257903