Undeprecate VariableDescriptorWithAccessors.isDelegated

Apparently there's quite a few valid usages of this method outside of
the compiler frontend, where manual suppression is annoying.

https://github.com/JetBrains/kotlin/commit/8c71d8f1262cfcd1591e5ad95f62eab524498f6c
(cherry picked from commit 0aa1ab4cccee3059cf2c1a755434de53b4c35ed2)

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/BuiltInFictitiousFunctionIrClassFactory.kt

@@ -307,8 +307,6 @@ internal class BuiltInFictitiousFunctionIrClassFactory(
 
         fun createFakeOverrideProperty(descriptor: PropertyDescriptor): IrProperty {
             val propertyDeclare = { s: IrPropertySymbol ->
-                @Suppress("DEPRECATION")
-                /* TODO: [PropertyDescriptor::isDelegated] is deprecated. */
                 IrPropertyImpl(
                         startOffset = offset,
                         endOffset = offset,