YQL-20917: Check inline subquery LangVer at DoInit

Previously, a "bad tree" with a pure `ISource` instead of the expression
`INode` got into the named expression. Since the named expression was
not used, the `Translate` was not performed and there was  no panic.
But recently it was fixed, but the `LangVer` started to be checked
on `INode` tree contruction, so it breaks backward compatibility. This is
why I postpone this check to the `DoInit` translation stage.
commit_hash:b68c83b499391dc629bde8eeef262a696a006355

0 files changed, 0 insertions, 0 deletions