[Ada] Fix wrong value returned for unconstrained packed array

[Ada] Fix wrong value returned for unconstrained packed array

2018-05-31  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* gcc-interface/trans.c (Call_to_gnu): In the by-reference case, if
	the type of the parameter is an unconstrained array type, convert
	to the type of the actual before the type of the formal only if the
	conversion was suppressed earlier.  Use in_param and gnu_actual_type
	local variables throughout, and uniform spelling for In Out or Out.
	Also remove dead code in the component-by-reference case.

From-SVN: r261011