move getVirtualIndex to functions

Author: ntrel

spec/traits.dd

@@ -364,6 +364,15 @@ static assert(!__traits(isDisabled, Bar));
 ---
 )
 
+$(H3 $(GNAME getVirtualIndex))
+
+  $(P Takes a single argument which must evaluate to a function.
+  The result is a $(CODE ptrdiff_t) containing the index
+  of that function within the vtable of the parent type.
+  If the function passed in is final and does not override
+  a virtual function, $(D -1) is returned instead.
+  )
+
 $(H3 $(GNAME isVirtualFunction))
 
         $(P The same as $(GLINK isVirtualMethod), except
@@ -1475,15 +1484,6 @@ $(H3 $(GNAME classInstanceSize))
         polymorphic type.
         )
 
-$(H3 $(GNAME getVirtualIndex))
-
-  $(P Takes a single argument which must evaluate to a function.
-  The result is a $(CODE ptrdiff_t) containing the index
-  of that function within the vtable of the parent type.
-  If the function passed in is final and does not override
-  a virtual function, $(D -1) is returned instead.
-  )
-
 $(H3 $(GNAME allMembers))
 
         $(P Takes a single argument, which must evaluate to either