Write metadata for suspend function into anonymous coroutine classes

To render nice Kotlin types in toString() of continuation

compiler/testData/codegen/box/coroutines/coroutineToString.kt

@@ -0,0 +1,33 @@
+// TARGET_BACKEND: JVM
+// WITH_REFLECT
+// WITH_COROUTINES
+
+import helpers.*
+import kotlin.coroutines.experimental.*
+import kotlin.coroutines.experimental.intrinsics.*
+
+class A<T : String> {
+    suspend fun foo() {}
+
+    suspend fun bar(): T {
+        foo()
+        return suspendCoroutineOrReturn { x ->
+            x.resume(x.toString() as T)
+            COROUTINE_SUSPENDED
+        }
+    }
+}
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(EmptyContinuation)
+}
+
+fun box(): String {
+    var result = ""
+
+    builder {
+        result = A<String>().bar()
+    }
+
+    return if (result == "(kotlin.coroutines.experimental.Continuation<T>) -> kotlin.Any?") "OK" else "Fail: $result"
+}