[TaskGroup] Stop using group.spawn in warning messages

Author: ktoso

stdlib/public/Concurrency/TaskLocal.cpp

@@ -248,7 +248,7 @@ static void swift_task_reportIllegalTaskLocalBindingWithinWithTaskGroupImpl(
       "The following example is illegal:\n\n"
       "    await withTaskGroup(...) { group in \n"
       "        await <task-local>.withValue(1234) {\n"
-      "            group.spawn { ... }\n"
+      "            group.addTask { ... }\n"
       "        }\n"
       "    }\n"
       "\n"
@@ -257,21 +257,21 @@ static void swift_task_reportIllegalTaskLocalBindingWithinWithTaskGroupImpl(
       "    // bind task-local for all tasks spawned within the group\n"
       "    await <task-local>.withValue(1234) {\n"
       "        await withTaskGroup(...) { group in\n"
-      "            group.spawn { ... }\n"
+      "            group.addTask { ... }\n"
       "        }\n"
       "    }\n"
       "\n"
       "or, inside the specific task-group child task:\n"
       "\n"
       "    // bind-task-local for only specific child-task\n"
       "    await withTaskGroup(...) { group in\n"
-      "        group.spawn {\n"
+      "        group.addTask {\n"
       "            await <task-local>.withValue(1234) {\n"
       "                ... \n"
       "            }\n"
       "        }\n"
       "\n"
-      "        group.spawn { ... }\n"
+      "        group.addTask { ... }\n"
       "    }\n",
       (int)fileLength, file,
       (int)line);