[dart2wasm] Enabling `--enable-deferred-loading` in `language/deferred/regression_22995_test` results in binaryen wasm validation error

[mkustermann]

See log

/=========================================================================================\
| language/deferred/regression_22995_test broke (Pass -> CompileTimeError, expected Pass) |
\=========================================================================================/

--- Command "dart2wasm" (took 01.000252s):
DART_CONFIGURATION=ReleaseX64 out/ReleaseX64/dart-sdk/bin/dart compile wasm -O1 -Dtest_runner.configuration=dart2wasm-linux-optimized-jsc --extra-compiler-option=--enable-deferred-loading /b/s/w/ir/tests/language/deferred/regression_22995_test.dart -o /b/s/w/ir/out/ReleaseX64/generated_compilations/dart2wasm-linux-optimized-jsc/tests_language_deferred_regression_22995_test/regression_22995_test.wasm

exit code:
254

stderr:
Error: Wasm compilation failed while optimizing output
[wasm-validator error in module] publicly exposed type disallowed with a closed world: $(type $func.0 (func (result (ref null $struct.0)))), on 
(type $func.0 (func (result (ref null $struct.0))))
[wasm-validator error in module] publicly exposed type disallowed with a closed world: $#Top, on 
(type $struct.0 (sub (struct (field i32))))
[wasm-validator error in module] publicly exposed type disallowed with a closed world: $C, on 
(type $struct.0 (sub final $struct.1 (struct (field i32) (field (mut i32)))))
[wasm-validator error in module] publicly exposed type disallowed with a closed world: $Object, on 
(type $struct.0 (sub $struct.1 (struct (field i32) (field (mut i32)))))
[wasm-validator error in module] publicly exposed type disallowed with a closed world: $B, on 
(type $struct.0 (sub final $struct.1 (struct (field i32) (field (mut i32)))))
[wasm-validator error in module] publicly exposed type disallowed with a closed world: $A, on 
(type $struct.0 (sub final $struct.1 (struct (field i32) (field (mut i32)))))
Fatal: error validating input

--- Re-run this test:
python3 tools/test.py -n dart2wasm-linux-optimized-jsc language/deferred/regression_22995_test

/cc @natebiggs