Live bindings not binding for exports of let in compartment-mapper/bundle.js

[leotm]

Describe the bug

Context: discovered in

• feat(ses): Shim compatible with Hermes compiler #2334 (comment)

The transform used to provide live bindings is not transforming the subsequent references to a variable defined with let therefore the only reason the updated value propagates correctly is because moduleLexicals are (somewhere?) wired up to it. That's not the case in the bundler in compartment-mapper though.

Steps to reproduce

• test: tests live binding on a let (demonstrates: #2431) #2432

Expected behavior

TBD

Platform environment

Additional context

Screenshots