Cannot use `for` expressions on non-generic IEnumerable type

[Chuck]

This should work, but fails with false compilation errors:

class Test

	def main is shared
		ie as System.Collections.IEnumerable = [1, 2, 3]
		# works:
		# ie as IEnumerable<of int> = [1, 2, 3]
		print for x in ie get x

[Chuck]

Fixed in changeset:1780