Implement basic support for coroutines in JVM backend

compiler/testData/codegen/java8/box/asyncException.kt

@@ -0,0 +1,61 @@
+// WITH_RUNTIME
+// FULL_JDK
+
+import java.util.concurrent.CompletableFuture
+
+fun exception(v: String): CompletableFuture<String> = CompletableFuture.supplyAsync { throw RuntimeException(v) }
+
+fun foobar(x: String, y: String) = x + y
+
+fun box(): String {
+    var result = ""
+
+    val future = async<String>() {
+        try {
+            await(exception("OK"))
+        } catch (e: Exception) {
+            result = e.cause?.message!!
+        }
+        "56"
+    }
+
+    future.join()
+
+    if (future.get() != "56") return "fail: ${future.get()}"
+
+    java.lang.Thread.sleep(1000)
+
+    return result
+}
+
+fun <T> async(coroutine c: FutureController<T>.() -> Continuation<Unit>): CompletableFuture<T> {
+    val controller = FutureController<T>()
+    c(controller).resume(Unit)
+    return controller.future
+}
+
+class FutureController<T> {
+    val future = CompletableFuture<T>()
+
+
+    suspend fun <V> await(f: CompletableFuture<V>, machine: Continuation<V>) {
+        f.whenComplete { value, throwable ->
+            try {
+                if (throwable == null)
+                    machine.resume(value)
+                else
+                    machine.resumeWithException(throwable)
+            } catch (e: Exception) {
+                future.completeExceptionally(e)
+            }
+        }
+    }
+
+    fun handleResult(value: T, c: Continuation<Nothing>) {
+        future.complete(value)
+    }
+
+    fun handleException(t: Throwable, c: Continuation<Nothing>) {
+        future.completeExceptionally(t)
+    }
+}