Heterogeneous collection literals are inferred as <of Object> instead of <of dynamic>

[hopscc]

Follow up from ticket:170 and Forum Topic  Should This be an error

class X
   def main
      a = 'aoeu' to Object
      b = 5 to Object
      l = [a to String, b to int]
      x = l[0]
      y = l[1]
      assert x.length == 4
      assert y * 2 == 10

Fails with

castInList.cobra(8): error: Cannot find a definition for "length" in "x" whose
type is "Object".
castInList.cobra(9): error: Cannot apply STAR to Object and int. Try finding a
method that performs this function.
Compilation failed - 2 errors, 0 warnings

Currently, a list of heterogeneous types such as [true, 3] will yield an inferred type of List<of Object>, but unless the actual element types are all Object (or Object?), the inferred type should be List<of dynamic> instead. If that were the case, then the above would work and Cobra would gain another bit of that good ol' Python convenience.

This should apply to inference on set and dictionary literals as well.

[Chuck]

I think the correct Summary would be:

"Heterogeneous collection literals are inferred as <of Object> instead of <of dynamic>"

[hopscc]

patch, new tests, fix now assignment failure lit list to Object*,
relnote.

[Chuck]

Thanks. Applied in changeset:2250