This changes the compiler to build in place almost all objects that need
finalization and are initialized with the result of a function call, thus
saving a pair of Adjust/Finalize calls for the anonymous return object.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration): Don't adjust the object
	if the expression is a function call.
	<Rewrite_As_Renaming>: Return true if the object needs finalization
	and is initialized  with the result of a function call returned on
	the secondary stack.
	* exp_ch6.adb (Expand_Ctrl_Function_Call): Add Use_Sec_Stack boolean
	parameter.  Early return if the parent is an object declaration and
	Use_Sec_Stack is false.
	(Expand_Call_Helper): Adjust call to Expand_Ctrl_Function_Call.
	* exp_ch7.adb (Find_Last_Init): Be prepared for initialization still
	present in the object declaration.
	* sem_ch3.adb (Analyze_Object_Declaration): Call the predicates
	Needs_Secondary_Stack and Needs_Finalization to guard the renaming
	optimization.