[Eager Execution] Add short-circuiting for EagerAstChoice

[jasmith-hs]

Add short-circuiting for EagerAstChoice.
Similar to #737 which was done to add short-circuiting for EagerAstBinary, it should also be done for EagerAstChoice.

For example:

deferred ? foo_list.add(foo) : foo_list.add(1 + 1)

should become:

deferred ? foo_list.add('foo val') : foo_list.add(2)

and not:

deferred ? true : true