The PPU/SPU recompilers emit i8mm intrinsics (ummla/smmla, used by the
SPU GBB/GBH gather paths) gated on utils::has_i8mm(). The JIT's MAttrs
list mirrored dotprod/sha3/sve from HWCAP but never added i8mm, and the
resolved -mcpu on Apple silicon is the cortex-a78 fallback (no i8mm), so
the backend aborted with "Cannot select: intrinsic %llvm.aarch64.neon.ummla"
on every game. Mirror i8mm into MAttrs like the other features.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
(cherry picked from commit 52d121fee79cc569c9ac273852edd0e493ae51fc)