- replaces "move-only" terminology with "noncopyable"
- replaces compiler jargon like "guaranteed parameters"
and "lvalue" with corresponding language-level notions
- simplifies diagnostics about closures.
and probably more.
rdar://109281444
the main things still left behind the experimental flag(s) are
- move-only classes (guarded by MoveOnlyClasses feature)
- noimplicitcopy
- the _borrow operator