Imitate support for suspend modifier on parameterless lambdas

#KT-22766 In Progress

compiler/testData/codegen/box/coroutines/suspendFunctionTypeCall/suspendModifier.kt

@@ -0,0 +1,31 @@
+// WITH_RUNTIME
+// WITH_COROUTINES
+import helpers.*
+import kotlin.coroutines.experimental.*
+import kotlin.coroutines.experimental.intrinsics.*
+
+suspend fun suspendHere(v: String): String = suspendCoroutineOrReturn { x ->
+    x.resume(v)
+    COROUTINE_SUSPENDED
+}
+
+suspend fun foo(): String {
+    var a = "OK"
+    var i = 0
+    val x = suspend {
+        suspendHere(a[i++].toString())
+    }
+
+    return x() + x.invoke()
+}
+
+
+fun box(): String {
+    var result = ""
+
+    suspend {
+        result = foo()
+    }.startCoroutine(EmptyContinuation)
+
+    return result
+}

compiler/testData/diagnostics/testsWithStdLib/coroutines/suspendLambda.kt

@@ -0,0 +1,20 @@
+import kotlin.coroutines.experimental.Continuation
+import kotlin.coroutines.experimental.CoroutineContext
+import kotlin.coroutines.experimental.startCoroutine
+
+fun bar() {
+    suspend {
+        println()
+    }.startCoroutine(object: Continuation<Unit> {
+        override val context: CoroutineContext
+            get() = TODO("not implemented")
+
+        override fun resume(value: Unit) {
+            TODO("not implemented")
+        }
+
+        override fun resumeWithException(exception: Throwable) {
+            TODO("not implemented")
+        }
+    })
+}

compiler/testData/diagnostics/testsWithStdLib/coroutines/suspendLambda.txt

@@ -0,0 +1,3 @@
+package
+
+public fun bar(): kotlin.Unit