The backend follows the ARM64 one: a dispatcher, a register cache on top of the IR one, and
native exits, syscalls, breakpoints and transfers. Everything else goes to the IR interpreter
for now. Floats are mapped one lane per S register (no SIMD mapping yet), and addresses are
masked, as on every 32-bit build.
The JIT core now uses it on ARM32 in place of the old ArmJit.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
