DIP8: Templating ClassInfo and TypeInfo

[dsimcha]

http://prowiki.org/wiki4d/wiki.cgi?LanguageDevel/DIPs/DIP8

Abstract:

Currently, the layout of D's runtime type info, or RTTI, is defined in
object.d. The details of how the fields of each instantiation of these classes
are populated are buried deep inside the compiler. If ClassInfo and TypeInfo
were instead template classes inheriting from some non-templated abstract base
class that defined the interface and field layout, any compile-time
introspection feature could trivially be added to RTTI and made available at
runtime.