build: add a flag v8_enable_simulator
The v8 simulator can help we run test for non-x64 backend on x64 machine. So I add a flag to build v8 smulator.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
The v8 simulator can help we run test for non-x64 backend on x64 machine. So I add a flag to build v8 smulator.