refactor to avoid compiler crash

Summary:
g++ 8.2.1 on some platforms crashes on the gtests defined
in EventBaseTestLib.h that declare inner classes.  This diff
refactors the tests so that they can be successfully compiled.

Reviewed By: yfeldblum

Differential Revision: D19871529

fbshipit-source-id: 3e84c2983e90b7445c014c002bbac504e0366657

folly/io/async/test/EventBaseTestLib.h

@@ -840,11 +840,8 @@ TYPED_TEST_P(EventBaseTest, WritePartial) {
   }
 }
 
-/**
- * Test destroying a registered EventHandler
- */
-TYPED_TEST_P(EventBaseTest, DestroyHandler) {
-  class DestroyHandler : public AsyncTimeout {
+namespace {
+class DestroyHandler : public AsyncTimeout {
  public:
   DestroyHandler(EventBase* eb, EventHandler* h)
       : AsyncTimeout(eb), handler_(h) {}
@@ -855,8 +852,13 @@ TYPED_TEST_P(EventBaseTest, DestroyHandler) {
 
  private:
   EventHandler* handler_;
-  };
+};
+} // namespace
 
+/**
+ * Test destroying a registered EventHandler
+ */
+TYPED_TEST_P(EventBaseTest, DestroyingHandler) {
   FOLLY_SKIP_IF_NULLPTR_BACKEND(eb);
   SocketPair sp;
 
@@ -1115,11 +1117,8 @@ TYPED_TEST_P(EventBaseTest, CancelTimeout) {
   T_CHECK_TIMEOUT(start, end, std::chrono::milliseconds(50));
 }
 
-/**
- * Test destroying a scheduled timeout object
- */
-TYPED_TEST_P(EventBaseTest, DestroyTimeout) {
-  class DestroyTimeout : public AsyncTimeout {
+namespace {
+class DestroyTimeout : public AsyncTimeout {
  public:
   DestroyTimeout(EventBase* eb, AsyncTimeout* t)
       : AsyncTimeout(eb), timeout_(t) {}
@@ -1130,8 +1129,13 @@ TYPED_TEST_P(EventBaseTest, DestroyTimeout) {
 
  private:
   AsyncTimeout* timeout_;
-  };
+};
+} // namespace
 
+/**
+ * Test destroying a scheduled timeout object
+ */
+TYPED_TEST_P(EventBaseTest, DestroyingTimeout) {
   FOLLY_SKIP_IF_NULLPTR_BACKEND(eb);
 
   TestTimeout* t1 = new TestTimeout(&eb);
@@ -2295,14 +2299,14 @@ REGISTER_TYPED_TEST_CASE_P(
     ReadWritePersist,
     ReadPartial,
     WritePartial,
-    DestroyHandler,
+    DestroyingHandler,
     RunAfterDelay,
     RunAfterDelayDestruction,
     BasicTimeouts,
     ReuseTimeout,
     RescheduleTimeout,
     CancelTimeout,
-    DestroyTimeout,
+    DestroyingTimeout,
     ScheduledFn,
     ScheduledFnAt,
     RunInThread,