Triple-shift operator

[lrhn]

Dart integers are now 64-bit signed numbers. That makes the >>> logical down-shift operator useful again. (It existed once, but with arbitrary size integers, the it didn't make sense to do unsigned shifiting any more).

This is a request for the >>> operator. It makes sense in other cases too (like the Int64 class).

Associated feature specification has more details.

Implementation issue: #478

[rashedmyt]

@lrhn In the 2nd para of the Background section in feature-specification, it is mentioned that dart integers are unsigned 64 bit which is the opposite of what said in the above comment..

[lrhn]

Thanks, good catch. That should definitely be signed 64-bit integers.
Fixed.