Debugger should not manage exceptions during shutdown

[mikelle-rogers]

When we are in the process of shutting down the EE, we do not want the debugger to manage any exceptions. The EE should continue to shut down and the debugger should ignore the exception.

Fixes #90079

[hoyosjs]

How does this behave if the case that triggered this is an int3/bp that we set? Will we race to crash with the runtime that's shutting down?

[noahfalk]

Agreed with @hoyosjs - in cases where the debugger set a breakpoint by overwriting a pre-existing instruction ignoring the OS notification probably results in a crash, hang, or executing unintended assembly instructions. Two potential solutions:

1. Skip over the breakpoint as normal but potentially forego delivering the cross-process debugger notification.
2. Remove all breakpoint patches at an earlier point in shutdown so that no exception is generated in the first place.

[jkotas]

Skip over the breakpoint as normal but potentially forego delivering the cross-process debugger notification.

I think this is the best way to fix the issue.

Remove all breakpoint patches at an earlier point in shutdown so that no exception is generated in the first place

We would need to ensure that no threads are executing the patches before proceeding. To do that, we would need to suspend the runtime that can come with a new set of issues. In general, we try to minimize amount of code that runs during shutdown. We just try to do the absolute minimum required to allow shutdown to progress. The first option fits the bill better.

[noahfalk]

I'm fine with the first option, having two was mostly to afford some flexibility in case one ran into unforeseen issues. Agreed that the 2nd option requires more deliberate work in the shutdown code path.

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