[BUG]: `IRContext.Import(Method)` does not correctly duplicate the full IR graph

[IsaMorphic]

Describe the bug

When calling IRContext.Import(Method), it is evident (through ongoing investigation) that there are some parts of the IR graph that remain untraversed, even though IRRebuilder.CloneMode is being used for this purpose.

Environment

• ILGPU version: 2.0.0-beta1
• .NET version: 8
• Operating system: [Windows 11]

Steps to reproduce

1. Check-out ir-importer on my fork of this project
2. Run unit tests
3. Observe that all of them fail due to KeyNotFoundException, indicating that IRContext.Import(Method) did not perform a complete traversal of the input Method instance and all of its dependencies (i.e. some dependencies are missing altogether).

Expected behavior

I should be able to run the unit tests without observing this failure.

Additional context

On this fork of ILGPU, I am developing an IR export/import pipeline that can persist an in-memory IRContext for future recall / use at runtime. This is for the NativeAOT support feature.

[IsaMorphic]

From some dynamic analysis, it appears that IRRebuilder.CloneMode "forgets" to clone Parameter values for each Method. Just a hunch, though.

[IsaMorphic]

I ended up finding that this was a bug on the consumer side of the API, related to read-locking of the IRContext. Consider this a misreport!