[IR BE] Drop unused members in backend context (K/N part)

(cherry picked from commit cad57e996db7b9d933855bbd91a623a0f8f34003)

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

@@ -187,7 +187,6 @@ internal class SpecialDeclarationsFactory(val context: Context) {
 }
 
 internal class Context(config: KonanConfig) : KonanBackendContext(config) {
-    override val lateinitNullableFields = mutableMapOf<IrField, IrField>()
     lateinit var frontendServices: FrontendServices
     lateinit var environment: KotlinCoreEnvironment
     lateinit var bindingContext: BindingContext

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

@@ -36,8 +36,6 @@ internal abstract class KonanBackendContext(val config: KonanConfig) : CommonBac
 
     abstract override val ir: KonanIr
 
-    override val transformedFunction: MutableMap<IrFunctionSymbol, IrSimpleFunctionSymbol>
-        get() = TODO("not implemented")
     override val scriptMode: Boolean = false
 
     override val sharedVariablesManager by lazy {