Collisions missed in Bullet Physics but not Godot Physics

[duckinator]

Godot version:
3.0

OS/device including version:
Fedora 29

Issue description:

With Bullet Physics, I'm able to consistently get objects to go through walls, even with CCD enabled.

Switching to Godot Physics and setting Physics FPS to 120 fixes it. Either alone doesn't fix it.

Steps to reproduce:

Apply an impulse to a RigidBody so that it goes flying at another RigidBody at high speed.

When the speed exceeds a certain point, it simply passes through.

Minimal reproduction project:

https://github.com/duckinator/godot-bullet-issue-testcase

Branch master is the testcase, branch fixed is a fixed variant as described above.

[duckinator]

Opened this as suggested by @reduz: https://twitter.com/reduzio/status/1123756724299735040

[eon-s]

Cannot reproduce on 3.1 even with the bullets at 500 units of impulse, can you try it on that version?

Related to #16113 but that one is rigid against static and fails at really low speeds.

[duckinator]

I can't reproduce in 3.1, either. So nevermind I guess lol