Disable cloned breakpoints trace point events

[vinistock]

Description

We're currently not invoking bp.disable or bp.delete on the cloned breakpoint. This means that the associated trace point event continues to be enabled.

Most of the time, that's not an issue because the target @iseq will not match. But there are some cases where old @iseq objects may continue to exist and we will continue having the execution suspended by the old trace point.

One example scenario of this is when using aliases, which hold references to the old @iseq (see the test, which reproduces the issue).

Depending on the order of events, this sometimes leads to execution being suspended by breakpoints that were already removed - because the trace point event is still enabled, even if the breakpoint was removed from the hash. Disabling the trace point for the removed breakpoint ensures that we can't get the execution suspended by these removed breakpoints.

[vinistock]

Here, we don't need to check breakpoints that are not covered by the iseq.

[vinistock]

LineBreakpoint.copy always returns a breakpoint, so the if here is not necessary.

[ko1]

I feel this kind of duplication check will introduce another issue (e.g. ISeq search order and so on) but try it.

[vinistock]

For what is worth, we've been trying it for a while and haven't noticed any other side effects. But it does fix the issue with ghost breakpoints. Thanks for merging!