Move the emulator into crates/gba-core, the original demo programs into
crates/gba-demos, and the minifb frontend into crates/desktop. The binary
is now gameboy-rust. Imports change from gba_rust to gba_core/gba_demos;
no behavior changes.
gba-core has no dependencies. Its integration tests use gba-demos as a
development dependency.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Add SWI 0x16, 0x17, and 0x18 as original ARM routines. Reconstruct samples with modular addition and byte or halfword output. Validate headers, alignment, lengths, and address ranges; preserve earlier completed writes on failure.
Add 17 regression tests for sample round trips, wraparound, large byte lengths, caller state, partial failures, bus behavior, and DMA/IRQ progress. Validate 635 default and 624 core-only tests in debug and release, plus all 10 native Darwin ARM64 window smoke tests.
