Added test on suspend conversions

backend.native/tests/build.gradle

@@ -1806,6 +1806,12 @@ task coroutines_functionReference_lambdaAsSuspendLambda(type: KonanLocalTest) {
     source = "codegen/coroutines/functionReference_lambdaAsSuspendLambda.kt"
 }
 
+standaloneTest('coroutines_suspendConversion') {
+    goldValue = ""
+    source = "codegen/coroutines/suspendConversion.kt"
+    flags = ['-XXLanguage:+SuspendConversion']
+}
+
 task AbstractMutableCollection(type: KonanLocalTest) {
     expectedExitStatus = 0
     source = "runtime/collections/AbstractMutableCollection.kt"

backend.native/tests/codegen/coroutines/suspendConversion.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+import kotlin.test.*
+
+import kotlin.coroutines.*
+import kotlin.coroutines.intrinsics.*
+
+open class EmptyContinuation(override val context: CoroutineContext = EmptyCoroutineContext) : Continuation<Any?> {
+    companion object : EmptyContinuation()
+    override fun resumeWith(result: Result<Any?>) { result.getOrThrow() }
+}
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(EmptyContinuation)
+}
+
+fun main() {
+    var result = 0
+
+    val f: () -> Unit = { result = 42 }
+    builder(f)
+
+    assertEquals(42, result)
+}