Move TraitsExp semantic methods into free functions in traits.c
Merge pull request #3289 from 9rnsr/refactor_addressOf

[Refactoring] Remove `Scope *sc` from `Expression::addressOf`
Merge pull request #3292 from yebblies/traits

[DDMD] [refactor] Move TraitsExp semantic methods into free functions in traits.c
[Refactoring] Share FuncDeclaration for _aaLen
fix Issue 12214 - AA.length is not nothrow