Proposal: Evolve bare-arm into architecture-agnostic "bare" port

[kimstik]

The bare-arm port is brilliant in its simplicity - it's the "hello world" of MicroPython porting.
However, the name ties it to ARM while the concept is universal.

The hardware abstraction layer is already minimal (just a few functions). With minor refactoring, this could become ports/bare/ - a true architecture-agnostic reference port with pluggable backends (ARM, RISC-V, etc).

Why this matters more than adding separate bare-rv, bare-xtensa, etc:

• One reference port to rule them all
• Shared code stays shared
• New architecture = just few lines of code
• Less maintenance, more clarity

Proof of concept: I ported bare-arm to WCH CH592 (RISC-V). Results:

• With compiler: ~60KB
• Without compiler: ~30KB

The delta from bare-arm was minimal - mostly linker script and startup code.

Would the maintainers be open to a PR that generalizes bare-arm into a multi-arch sandbox?