[AOT] Explicitly support heterogeneous execution with AOT Executor

[areusch]

Currently, AOTExecutor only supports heterogeneous execution by leveraging tir.call_extern via BYOC. In order to properly model a heterogeneous environment (in particular, to model multiple disjoint memories and leverage #8404), AOTExecutor needs to formally support invoking the Device API. It's currently not possible to do this from TIR via the AOT run-function.

• [ ] Open a discuss forum post to debate how to properly model this in TIR, considering VirtualDevice
• [ ] Write up a formal RFC
• [ ] (yet TBD)

cc @Mousius @alanmacd @lhutton1

[driazati]

@areusch is this still planned?

[areusch]

yes