Fix evalLast() test to actually test what we wanted to test.

c++/src/kj/async-test.c++

@@ -404,11 +404,11 @@ TEST(Async, Ordering) {
     }).then([&]() {
       EXPECT_EQ(5, counter++);
       promises[8] = kj::evalLast([&]() {
-        EXPECT_EQ(9, counter++);
+        EXPECT_EQ(7, counter++);
         promises[9] = kj::evalLater([&]() {
-          EXPECT_EQ(10, counter++);
-        });
-      });
+          EXPECT_EQ(8, counter++);
+        }).eagerlyEvaluate(nullptr);
+      }).eagerlyEvaluate(nullptr);
     }).eagerlyEvaluate(nullptr);
 
     {
@@ -416,11 +416,11 @@ TEST(Async, Ordering) {
       promises[4] = paf.promise.then([&]() {
         EXPECT_EQ(2, counter++);
         promises[6] = kj::evalLast([&]() {
-          EXPECT_EQ(7, counter++);
+          EXPECT_EQ(9, counter++);
           promises[7] = kj::evalLater([&]() {
-            EXPECT_EQ(8, counter++);
-          });
-        });
+            EXPECT_EQ(10, counter++);
+          }).eagerlyEvaluate(nullptr);
+        }).eagerlyEvaluate(nullptr);
       }).eagerlyEvaluate(nullptr);
       paf.fulfiller->fulfill();
     }