[K/N] Use suspend function desugaring lowerings.

kotlin-native/runtime/src/main/kotlin/kotlin/native/internal/Coroutines.kt

@@ -25,6 +25,3 @@ internal inline suspend fun getCoroutineContext(): CoroutineContext =
 @TypedIntrinsic(IntrinsicType.RETURN_IF_SUSPENDED)
 @PublishedApi
 internal external suspend fun <T> returnIfSuspended(@Suppress("UNUSED_PARAMETER") argument: Any?): T
-
-@TypedIntrinsic(IntrinsicType.COROUTINE_LAUNCHPAD)
-internal external fun coroutineLaunchpad(suspendFunctionCall: Any?, continuation: Continuation<*>): Any?

kotlin-native/runtime/src/main/kotlin/kotlin/native/internal/IntrinsicType.kt

@@ -61,7 +61,6 @@ class IntrinsicType {
         // Coroutines
         const val GET_CONTINUATION              = "GET_CONTINUATION"
         const val RETURN_IF_SUSPENDED           = "RETURN_IF_SUSPENDED"
-        const val COROUTINE_LAUNCHPAD           = "COROUTINE_LAUNCHPAD"
 
         // Interop
         const val INTEROP_READ_PRIMITIVE        = "INTEROP_READ_PRIMITIVE"