Prevent the static contract optimizer from changing constructors under `or/sc`.
i.e., for static contracts of the form `(or/sc other-scs ...)`,
the optimizer cannot optimize any of the `other-scs ...` to `any/sc`
but it can optimize sub-contracts of the `other-scs ...`
Example:
`(or/sc set?/sc (box/sc set?/sc))` in a trusted position now optimizes to itself,
instead of `any/sc`
Optimization can resume under a sub-contract that represents a "heavy" type constructor.
(I mean, `U` is a type constructor but it's not "heavy" like that.)
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