Better handling of noncopyable objects and objects with this(this)

[Andrei Alexandrescu via Digitalmars-d]

FYI I just created https://issues.dlang.org/show_bug.cgi?id=14638 as one 
of possibly several language enhancements to improve usability of 
noncopyable types (most allocators are not copyable) and to enhance 
performance of objects that define this(this). -- Andrei