In case the cast value is used as a receiver to a private method call,
the cast is actually necessary, see KT-48927. Also, this optimization
has backfired once already (see kt48659_identityEqualsWithCastToAny.kt).
It seems that the best way to optimize these casts is not to generate
them in the first place, and/or use bytecode postprocessing.
Apparently the only kind of casts which need to be eliminated are those
which occur on an inline class to its supertype. Otherwise the
unsafe-coerce intrinsic is inserted at the incorrect place, and several
tests fail (uncastInlineClassToAnyAndBack.kt, genericOverride.kt,
classGenericOverride.kt).
#KT-48927 Fixed
Alexander Udalov