JVM IR: do not try to optimize casts in TypeOperatorLowering

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

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/lower/TypeOperatorLowering.kt

@@ -93,8 +93,7 @@ private class TypeOperatorLowering(private val context: JvmBackendContext) : Fil
                     )
                 }
             }
-        // Do not optimize casts for values of primitive types because it can affect their identity and thus change behavior.
-        !argument.type.isPrimitiveType() && argument.type.isSubtypeOfClass(type.erasedUpperBound.symbol) ->
+        argument.type.isInlineClassType() && argument.type.isSubtypeOfClass(type.erasedUpperBound.symbol) ->
             argument
         else ->
             builder.irAs(argument, type)