ada: Update libraries with the limited flag

ada: Update libraries with the limited flag

Records without a limited keyword now emit a warning if
they contain a member that has an inherently limited type.

gcc/ada/

	* libgnat/a-coinho__shared.ads: add limited keyword.
	* libgnat/g-awk.adb: add limited keyword.
	* libgnat/g-comlin.ads: add limited keyword.
	* libgnat/s-excmac__arm.ads: add limited keyword.
	* libgnat/s-excmac__gcc.ads: add limited keyword.
	* libgnat/s-soflin.ads: add limited keyword.