[browser] Move reflection from JS to C#

[pavelsavara]

This decreases hazard of dealing with managed types in JS.
It also reduces the need to MONO_ENTER_GC_UNSAFE
It will allow to initiate bind_assembly_exports from UI to deputy thread.
Allocate gc-roots for monoStringToStringUnsafe earlier.

Contributes to #98366

[ghost]

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Issue Details

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This decreases hazard of dealing with managed types in JS.
It also reduces the need to MONO_ENTER_GC_UNSAFE

Contributes to #98366

Author:	pavelsavara
Assignees:	pavelsavara
Labels:	arch-wasm, area-System.Runtime.InteropServices.JavaScript, os-browser
Milestone:	9.0.0

[pavelsavara]

/azp run runtime-wasm

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[maraf]

Looks good to me 👍

[pavelsavara]

/azp run runtime-wasm

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[pavelsavara]

/azp run runtime-wasm

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[pavelsavara]

I filled #98486

[radekdoulik]

Looks like this change increased the cold browser template startup time, probably increased the size. The range is 741c0c8...c34474e

Is there anything we can do to improve it?

[lewing]

I think we should discuss this more, it pulls in a lot more managed code and the long term fix is different.

[pavelsavara]

We can move it back to C/mono, but call it from C# side.
I think that Blazor is full of similar reflection anyway ?

[pavelsavara]

Is there anything we can do to improve it?

I moved it back to C, but called from the managed thread. #98534

Could you please check the perf with this ? @radekdoulik many thanks!