It's not really necessary if the information about if the lambda was a
trailing lambda can be directly saved in FirAnonymousFunctionExpression.
Removing the FIR node uncovered a couple of bugs
(UNINITIALIZED_ENUM_ENTRY, ERROR_IN_CONTRACT_DESCRIPTION) that were
caused by assuming that a lambda is always a trailing lambda.
#KT-66124
Before this commit, we added Enum.entries only in case when
LanguageFeature.EnumEntries was ON (with an exception in K1/Java case).
In this commit we add Enum.entries unconditionally, and in case
the language feature is OFF we filter them out during tower resolve.
Kirill Rakhman