x ~/ y should allow doubles in compile time constants

Example of a program dartc rejects, but that should be allowed:
&equals;&equals;&equals;
final x = 5.5;
final y = 2.2;
final z = x ~/ y;
main() =&gt; print(z);
&equals;&equals;&equals;
file:bug.dart:3: Expected constant expression of type int, got double
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2: final y = 2.2;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3: final z = x ~/ y;
Compilation failed with 1 problem.
