Failures on Revert "[model] Update handling of ?.length in constants"

[johnniwinther]

There are new test failures on Revert "[model] Update handling of ?.length in constants".

The tests

co19/Language/Expressions/Constants/string_length_t04 MissingCompileTimeError (expected Pass)

are failing on configurations

cfe-strong-linux

[sgrekhov]

After https://dart-review.googlesource.com/c/sdk/+/433321 co19/Language/Expressions/Constants/string_length_t04 passes on either CFE and analyzer. Closing this issue.