spec: class: add __ctor, __dtor and __xdtor aliases

Signed-off-by: Luís Ferreira <[email protected]>

Author: ljmf00

spec/class.dd

@@ -371,6 +371,9 @@ $(GNAME Constructor):
         }
         ------
 
+        $(P The compiler may generate a $(D __ctor) alias that matches with
+        constructors definitions.)
+
 $(H3 $(LNAME2 delegating-constructors, Delegating Constructors))
 
         $(P A constructor can call another constructor for the same class
@@ -729,6 +732,11 @@ $(GNAME Destructor):
         by the gc.
         )
 
+        $(P The compiler may generate $(D __dtor) and $(D __xdtor) alias that
+        matches the class destructor definition and inclusive destructors,
+        respectively.)
+
+
 $(H2 $(LNAME2 static-constructor, Static Constructors))
 
 $(GRAMMAR