This change removes an old trick which was propagating the Atomic (and now
Volatile_Full_Access) setting from an object to a locally-defined type, in
order to coax gigi into accepting more atomic objects.

This trick is now obsolete since gigi should be able to rewrite the type of
the objects to meet the atomicity requirements on its own.

The change also rewrites Is_Atomic_VFA_Aggregate to check for the presence
of the flag on the object as well, which was missing but largely mitigated
by the aforementioned trick.

No functional changes.

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

2015-05-26  Eric Botcazou  <ebotcazou@adacore.com>

	* freeze.ads (Is_Atomic_VFA_Aggregate): Adjust profile.
	* freeze.adb (Is_Atomic_VFA_Aggregate): Change Entity
	parameter into Node parameter and remove Type parameter.
	Look at Is_Atomic_Or_VFA both on the type and on the object.
	(Freeze_Entity): Adjust call to Is_Atomic_VFA_Aggregate.
	* exp_aggr.adb (Expand_Record_Aggregate): Likewise.
	(Process_Atomic_Independent_Shared_Volatile): Remove code
	propagating Atomic or VFA from object to locally-defined type.