Refine definition of whether call is suspension point

It's not about all calls to suspend functions, they may called from non-coroutine code

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

@@ -0,0 +1,36 @@
+class Controller {
+    suspend fun suspendHere(x: Continuation<String>) {
+        x.resume("OK")
+    }
+}
+
+fun builder(coroutine c: Controller.() -> Continuation<Unit>) {
+    c(Controller()).resume(Unit)
+}
+
+fun box(): String {
+    var result = "fail"
+
+    val lambda: Controller.() -> Continuation<Unit> = {
+        object : Continuation<Any?> {
+            override fun resume(data: Any?) {
+                if (data == Unit) {
+                    suspendHere(this)
+                    return
+                }
+
+                if (data != "OK") {
+                    throw java.lang.RuntimeException("fail: $data")
+                }
+
+                result = "OK"
+            }
+
+            override fun resumeWithException(exception: Throwable) = throw exception
+        }
+    }
+
+    builder(lambda)
+
+    return result
+}

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

@@ -0,0 +1,23 @@
+class Controller {
+    suspend fun suspendHere(x: Continuation<String>) {
+        suspendThere(x)
+    }
+
+    suspend fun suspendThere(x: Continuation<String>) {
+        x.resume("OK")
+    }
+}
+
+fun builder(coroutine c: Controller.() -> Continuation<Unit>) {
+    c(Controller()).resume(Unit)
+}
+
+fun box(): String {
+    var result = ""
+
+    builder {
+        result = suspendHere()
+    }
+
+    return result
+}