Dynamic Module / Deferred loading test failing in dart2wasm optimized mode

[mkustermann]

The tests

language/deferred/regression_22995_test RuntimeError (expected Pass)
web/wasm/flute_stress_test RuntimeError (expected Pass)
web/wasm/multi_module_stress_test RuntimeError (expected Pass)

are failing on configurations

dart2wasm-linux-optimized-jsc

/cc @natebiggs Should the tests be skipped on the optimized builders (I guess they are incompatible with binaryen's closed world model)?