Support is/as operations on suspend callable reference conversion

compiler/testData/codegen/box/callableReference/adaptedReferences/suspendConversion/isAs.kt

@@ -0,0 +1,23 @@
+// !LANGUAGE: +SuspendConversion
+// WITH_RUNTIME
+// WITH_COROUTINES
+
+import helpers.*
+import kotlin.coroutines.*
+
+fun callMe(): String = "OK"
+
+suspend fun isSuspend(c: suspend () -> String) = c is suspend () -> String
+suspend fun callSuspend(c: suspend () -> String) = (c as suspend () -> String)()
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(EmptyContinuation)
+}
+
+fun box(): String {
+    var res = "FAIL"
+    builder {
+        res = if (isSuspend(::callMe)) callSuspend(::callMe) else "!isSuspend"
+    }
+    return res
+}