Add initial prototype.

3-mid/physics/interface/source/physics-shape.adb

@@ -0,0 +1,18 @@
+with
+     ada.unchecked_Deallocation;
+
+package body physics.Shape
+is
+
+   procedure free (Self : in out View)
+   is
+      procedure deallocate is new ada.unchecked_Deallocation (Item'Class, View);
+   begin
+      if Self /= null then
+         Self.destruct;
+      end if;
+
+      deallocate (Self);
+   end free;
+
+end physics.Shape;