NotImplementedException count increase in recent insertion

[RikkiGibson]

I am seeing an increase in NotImplementedExceptions thrown in ⁠Roslyn 0813.12 insertion to VS. See PIT.

I believe the following PR/file change is likely related
https://github.com/dotnet/roslyn/pull/79809/files?diff=split&w=1#diff-07399f17a690c95d4e31689e1023676fa4b43d37e86775b6611bd8e1f170de6aR293

See also exception stack from PerfView

It looks like the work resulting in this exception, no longer happens synchronously, but in some queue and the exception only observed when the task is awaited. So, maybe some other component which expected to see the task thrown upon call to ReportError2(), sees it thrown in some other context instead, where it is not handled in the same way.

@CyrusNajmabadi for visibility

[RikkiGibson]

PR #79809 cannot be automatically reverted, from the GitHub side at least.

[CyrusNajmabadi]

is there more data on the originating source of the NotImplException? The above shows where we report it.

[RikkiGibson]

I do also see the stack where NotImplementedException was thrown, but, I don't know how to get back to the stack that originally called ReportError2(). Possibly my perfview skills are not up to snuff.

[CyrusNajmabadi]

Fixed with #79915