Revert attributes to their defaults with default keywords

[Daniel Kozak via Digitalmars-d]

I often have code like this:

class A {
    final:
    nothrow:
    ...
    some methods
    ...
}
Problem comes when I need add methods which for eg.: throws or 
need to be virtual.

I can put them before final: but this is not perfect, because I 
prefer when methods are place in specific order (method abc call 
method asd so asd is bellow abc and so on).

So today I download dmd source and make some small modification 
(only few lines) and this is the result:

http://dpaste.dzfl.pl/472afc938397