* gcc-interface/trans.c (unchecked_conversion_lhs_nop): New predicate.
	(gnat_to_gnu) <N_Unchecked_Type_Conversion>: Return the expression
	if the conversion is on the LHS of an assignment and a no-op.
	<all> Do not convert the result to the result type if the Parent
	node is such a conversion.

From-SVN: r146450