Integrate libmspack's LZX decompressor for Xbox 360 and UE-style
compressed data. This replaces the need for external xcompress64.dll
which was hanging/crashing on certain files.
- Add mspack/ library (lzxd.c decompressor with Gildor's fixes)
- Implement memory-based mspack_system for in-memory decompression
- Support multiple LZX formats: raw streams, Xbox 360 block format,
and Dead Rising 2's per-block format with 4-byte size headers
- Add DecompressDeadRisingLZX() with per-block independent contexts
to handle the block-based compression correctly
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
