[NativeAOT] Avoid redundant unwind info lookup during stackwalks

[jkotas]

Unwind info was looked up twice on non-Windows: Once during initial frame inspection and second during the actual unwind. Cache the lookup results from the initial frame inspection and use them from the actual unwind later, same as it is done on Windows.

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Issue Details

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Unwind info was looked up twice on non-Windows: Once during initial frame inspection and second during the actual unwind. Cache the lookup results from the initial frame inspection and use them from the actual unwind later, same as it is done on Windows.

Author:	jkotas
Assignees:	jkotas
Labels:	area-NativeAOT-coreclr
Milestone:	-

[jkotas]

Todo API w/ Workstation GC:

Before this change:

| Requests/sec | 72,812 |

With this change:

| Requests/sec | 76,727 |

[jkotas]

This is follow up on #86690 (comment) . I have more changes on top this one to make stack unwinding faster on Unix.

[filipnavara]

Related: #75807

[jkotas]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[VSadov]

Unwind info was looked up twice on non-Windows

I think the code makes assumption that fetching this info is a relatively cheap operation - like indexing in a table, but it is more complex than that. And there is space in the MethodInfo to keep the info. Nice change!

[VSadov]

LGTM! Thanks!