[Ada] Minor tweaks to suppress warnings

[Ada] Minor tweaks to suppress warnings

2018-10-09  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* adaint.c (__gnat_get_executable_suffix_ptr): Add new line.
	(__gnat_locate_exec): Check that HOST_EXECUTABLE_SUFFIX is not
	empty before doing a string search for it.
	* socket.c (ATTRIBUTE_UNUSED): Define.
	(__gnat_disable_sigpipe): Add ATTRIBUTE_UNUSED on parameter.
	* terminals.c (ATTRIBUTE_UNUSED): Move around.
	(__gnat_setup_child_communication): Add ATTRIBUTE_UNUSED on
	parameter.
	(__gnat_send_header): Add ATTRIBUTE_UNUSED on parameters.

From-SVN: r264982