Fix pRequestInfo INVALID_POINTER_READ caused by GCs

[NGloreous]

Fix pRequestInfo INVALID_POINTER_READ caused by GCs

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Description

When using the IHttpSysRequestInfoFeature it's possible to hit invalid pointer read errors which causes a process crash. It's also possible to hit other issue caused by the invalid pointer. The error occurs when a GC moves to memory of the request's _backingBuffer before trying to access the RequestInfo property of IHttpSysRequestInfoFeature.

The fix is to adjust the pRequestInfo pointer similar to how other pointers in this class are adjusted.

Fixes #50445

[ghost]

Thanks for your PR, @NGloreous. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[Tratcher]

Once merged this will also need to be backported to release/8.0. There's a bot we can use for that.

[Tratcher]

/backport to release/8.0

[github-actions]

Started backporting to release/8.0: https://github.com/dotnet/aspnetcore/actions/runs/6040761798