ada: Apply restriction No_Implementation_Attributes to source nodes only

ada: Apply restriction No_Implementation_Attributes to source nodes only

Restriction No_Implementation_Attributes must not be applied to nodes
that come from expansion. In particular, it must not be applied to
Object_Size, which is implementation-defined attribute before Ada 2022,
but appears in expansion of tagged types since Ada 95.

gcc/ada/

	* sem_attr.adb (Analyze_Attribute): Move IF statement that
	checks restriction No_Implementation_Attributes for Ada 2005,
	2012 and Ada 2022 attributes inside Comes_From_Source condition
	that checks the same restriction for Ada 83 attributes.