Steps to reproduce:
1. Download 1168299_repro.zip and open "Test" scene
2. Enter play mode
3. Open animation window
4. Select animation GameObject
5. Play animation

Actual results: Editor crashes when Legacy animation event is triggered.

Reproduced with: 2019.3.0a11, 2019.2.0f1
Not reproducible with: 2019.1.12f1, 2019.2.0a6
Regression introduced in: 2019.2.a7

========== OUTPUTTING STACK TRACE ==================

0x00007FF682AABE42 (Unity) PPtr<AnimationClip>::operator->
0x00007FF682B1E07D (Unity) FireEvent
0x00007FF682AE675D (Unity) AnimationState::FireEvents
0x00007FF682AF8567 (Unity) AnimationState::UpdateAnimationState
0x00007FF682AF7B2D (Unity) Animation::UpdateAnimation
0x00007FF682AC16A3 (Unity) AnimationManager::Update
0x00007FF682AB2496 (Unity) `AnimationManager::InitializeClass'::`2'::PreLateUpdateLegacyAnimationUpdateRegistrator::Forward
0x00007FF68509AE87 (Unity) ExecutePlayerLoop
0x00007FF68509AFD0 (Unity) ExecutePlayerLoop
0x00007FF6850A01B3 (Unity) PlayerLoop
0x00007FF68350DF6B (Unity) PlayerLoopController::UpdateScene
0x00007FF68350BCB4 (Unity) Application::TickTimer
0x00007FF683E24EB0 (Unity) MainMessageLoop
0x00007FF683E2EB9A (Unity) WinMain
0x00007FF686DF5B92 (Unity) __scrt_common_main_seh
0x00007FFEA0AA7974 (KERNEL32) BaseThreadInitThunk
0x00007FFEA127A271 (ntdll) RtlUserThreadStart

========== END OF STACKTRACE ===========