Transitions to new language semantics

[russhy]

i disagree, polluting code with compiler specific sheningans is 
the root of all evil

don't bloat code that is already hard to read for features people 
want to test

it's meant to be transitive, something temporary, not something 
that needs to live on people's code

let's just stop with the @ bloat


other aspect of D needs love, it certainly not the -preview 
thing, that is a pure waste of time