ada: Further cleanup in finalization machinery

ada: Further cleanup in finalization machinery

This removes the setting of the Is_Ignored_Transient flag on the temporaries
needing finalization created by Expand_Ctrl_Function_Call when invoked from
within the dependent expressions of conditional expressions.

This flag tells the general finalization machinery to disregard the object.
But temporaries needing finalization present in action lists of dependent
expressions are picked up by Process_Transients_In_Expression, which deals
with their finalization and sets the Is_Finalized_Transient flag on them.

Now this latter flag has exactly the same effect as Is_Ignored_Transient
as far as the general finalization machinery is concerned, so setting the
flag is unnecessary.  In the end, the flag can be decoupled entirely from
transient objects and renamed into Is_Ignored_For_Finalization.

This also moves around the declaration of a local variable and turns a
library-level procedure into a nested procedure.

gcc/ada/

	* einfo.ads (Is_Ignored_Transient): Rename into...
	(Is_Ignored_For_Finalization): ...this.
	* gen_il-fields.ads (Opt_Field_Enum): Adjust to above renaming.
	* gen_il-gen-gen_entities.adb (Object_Kind): Likewise.
	* exp_aggr.adb (Expand_Array_Aggregate): Likewise.
	* exp_ch7.adb (Build_Finalizer.Process_Declarations): Likewise.
	* exp_util.adb (Requires_Cleanup_Actions): Likewise.
	* exp_ch4.adb (Expand_N_If_Expression): Move down declaration of
	variable Optimize_Return_Stmt.
	(Process_Transient_In_Expression): Turn procedure into a child of...
	(Process_Transients_In_Expression): ...this procedure.
	* exp_ch6.adb (Expand_Ctrl_Function_Call): Remove obsolete setting
	of Is_Ignored_Transient flag on the temporary if within a dependent
	expression of a conditional expression.