Crashes on Undo after creating a Non-empty Child GameObject.

Steps to Reproduce:
1. Create new Game object
2. Create a child non-empty Game object such as cube, sphere, cylinder etc
3. Undo via Hot Keys OR using Edit > Undo

Observe the Crash

Expected Result: Child game object should disappear.

Actual Result: Editor Crashed

Working fine on: 2018.1.0a4, 2018.1.0a3, 2018.1.0a1, 2017.3.0f2, 2017.2.0f3, 2017.1.0f3

Reproducible on: 2018.1.0a7, 2018.1.0a5, 2018.1.0b1

Environment :
Crash occurs in Windows and Mac.