package object + backward compat

Now that there are package objects and scala.math, the contents of
scala.Math belong in that package object. However I don't see a direct
way to do that and still have scala.Math working for backward
compatibility -- can't say "val Math = scala.math" like you would if it
were moving from regular object to regular object.

The best I could do was to move the whole contents into a trait, then
have object scala.Math and package object scala.math each extend that
trait. This works, but is there a better way? And if there isn't,
should I check that in?