More asserts in listener_test for debuggability (#9320)

Summary:
We ran into a flake I could not debug so instead added assertions in
case it happens again.

Command was:

```
TEST_TMPDIR=/dev/shm/rocksdb COMPILE_WITH_UBSAN=1 USE_CLANG=1 OPT=-g SKIP_FORMAT_BUCK_CHECKS=1 make J=80 -j80 ubsan_check
```

Failure output was:

```
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from EventListenerTest
[ RUN      ] EventListenerTest.DisableBGCompaction
UndefinedBehaviorSanitizer:DEADLYSIGNAL
==1558126==ERROR: UndefinedBehaviorSanitizer: SEGV on unknown address 0x000000000031 (pc 0x7fd9c04dda22 bp 0x7fd9bf8aa580 sp 0x7fd9bf8aa540 T1558147)
==1558126==The signal is caused by a READ memory access.
==1558126==Hint: address points to the zero page.
    #0 0x7fd9c04dda21 in __dynamic_cast /home/engshare/third-party2/libgcc/9.x/src/gcc-9.x/x86_64-facebook-linux/libstdc++-v3/libsupc++/../../.././libstdc++-v3/libsupc++/dyncast.cc:49:3
    #1 0x510c53 in __ubsan::checkDynamicType(void*, void*, unsigned long) (/data/sandcastle/boxes/eden-trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/listener_test+0x510c53)
    #2 0x50fb32 in HandleDynamicTypeCacheMiss(__ubsan::DynamicTypeCacheMissData*, unsigned long, unsigned long, __ubsan::ReportOptions) (/data/sandcastle/boxes/eden-trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/listener_test+0x50fb32)
    #3 0x510230 in __ubsan_handle_dynamic_type_cache_miss_abort (/data/sandcastle/boxes/eden-trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/listener_test+0x510230)
    #4 0x63221a in rocksdb::ColumnFamilyHandleImpl* rocksdb::static_cast_with_check<rocksdb::ColumnFamilyHandleImpl, rocksdb::ColumnFamilyHandle>(rocksdb::ColumnFamilyHandle*) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/./util/cast_util.h:19:20
    #5 0x71cafa in rocksdb::DBImpl::TEST_GetFilesMetaData(rocksdb::ColumnFamilyHandle*, std::vector<std::vector<rocksdb::FileMetaData, std::allocator<rocksdb::FileMetaData> >, std::allocator<std::vector<rocksdb::FileMetaData, std::allocator<rocksdb::FileMetaData> > > >*, std::vector<std::shared_ptr<rocksdb::BlobFileMetaData>, std::allocator<std::shared_ptr<rocksdb::BlobFileMetaData> > >*) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/db_impl/db_impl_debug.cc:63:14
    #6 0x53f6b4 in rocksdb::TestFlushListener::OnFlushCompleted(rocksdb::DB*, rocksdb::FlushJobInfo const&) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/listener_test.cc:277:24
    #7 0x6e2f7d in rocksdb::DBImpl::NotifyOnFlushCompleted(rocksdb::ColumnFamilyData*, rocksdb::MutableCFOptions const&, std::__cxx11::list<std::unique_ptr<rocksdb::FlushJobInfo, std::default_delete<rocksdb::FlushJobInfo> >, std::allocator<std::unique_ptr<rocksdb::FlushJobInfo, std::default_delete<rocksdb::FlushJobInfo> > > >*) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:863:19
    #8 0x6e1074 in rocksdb::DBImpl::FlushMemTableToOutputFile(rocksdb::ColumnFamilyData*, rocksdb::MutableCFOptions const&, bool*, rocksdb::JobContext*, rocksdb::SuperVersionContext*, std::vector<unsigned long, std::allocator<unsigned long> >&, unsigned long, rocksdb::SnapshotChecker*, rocksdb::LogBuffer*, rocksdb::Env::Priority) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:314:5
    #9 0x6e3412 in rocksdb::DBImpl::FlushMemTablesToOutputFiles(rocksdb::autovector<rocksdb::DBImpl::BGFlushArg, 8ul> const&, bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::Env::Priority) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:359:14
    #10 0x700df6 in rocksdb::DBImpl::BackgroundFlush(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::FlushReason*, rocksdb::Env::Priority) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:2703:14
    #11 0x6fe1f0 in rocksdb::DBImpl::BackgroundCallFlush(rocksdb::Env::Priority) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:2742:16
    #12 0x6fc732 in rocksdb::DBImpl::BGWorkFlush(void*) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:2569:44
    #13 0xb3a820 in void std::_Bind<void (* (void*))(void*)>::operator()<void>() /mnt/gvfs/third-party2/libgcc/4959b39cfbe5965a37c861c4c327fa7c5c759b87/9.x/platform009/9202ce7/include/c++/9.x/functional:482:17
    #14 0xb3a820 in std::_Function_handler<void (), std::_Bind<void (* (void*))(void*)> >::_M_invoke(std::_Any_data const&) /mnt/gvfs/third-party2/libgcc/4959b39cfbe5965a37c861c4c327fa7c5c759b87/9.x/platform009/9202ce7/include/c++/9.x/bits/std_function.h:300:2
    #15 0xb347cc in rocksdb::ThreadPoolImpl::Impl::BGThread(unsigned long) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/util/threadpool_imp.cc:266:5
    #16 0xb34a2f in rocksdb::ThreadPoolImpl::Impl::BGThreadWrapper(void*) /data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/util/threadpool_imp.cc:307:7
    #17 0x7fd9c051a660 in execute_native_thread_routine /home/engshare/third-party2/libgcc/9.x/src/gcc-9.x/x86_64-facebook-linux/libstdc++-v3/src/c++11/../../../.././libstdc++-v3/src/c++11/thread.cc:80:18
    #18 0x7fd9c041e20b in start_thread /home/engshare/third-party2/glibc/2.30/src/glibc-2.30/nptl/pthread_create.c:479:8
    #19 0x7fd9c01dd16e in clone /home/engshare/third-party2/glibc/2.30/src/glibc-2.30/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95
```

Pull Request resolved: #9320

Reviewed By: jay-zhuang

Differential Revision: D33242185

Pulled By: ajkr

fbshipit-source-id: 741984b10a610e0509e0d4e54c42cdbac03f5285

db/listener_test.cc

@@ -274,6 +274,9 @@ class TestFlushListener : public EventListener {
     ASSERT_TRUE(test_);
     if (db == test_->db_) {
       std::vector<std::vector<FileMetaData>> files_by_level;
+      ASSERT_LT(info.cf_id, test_->handles_.size());
+      ASSERT_GE(info.cf_id, 0u);
+      ASSERT_NE(test_->handles_[info.cf_id], nullptr);
       test_->dbfull()->TEST_GetFilesMetaData(test_->handles_[info.cf_id],
                                              &files_by_level);