HotSwap: unsupported instruction `__crash__` on gfx1250 -> gfx942/gfx950 lift

[soumitra-chatterjee-tech]

Summary

The HotSwap cross-family raiser does not lower the gfx1250 instruction __crash__ when
targeting gfx942 / gfx950 (wave32 -> wave64). Every kernel that emits it fails to transpile.

raise_cli output

-> __crash__ [signal_11]

Reproduce

1. Compile any HIP kernel that emits __crash__ for gfx1250 (a kernel using the
   corresponding operation/intrinsic).
2. Run: raise_cli --target-isa=gfx942 <kernel.gfx1250.hsaco> (and --target-isa=gfx950).
3. Observe the FAIL above; 0 kernels transpile.

Environment

• Transpiler: martin-luecke/llvm-project@hotswap
• Source ISA gfx1250 (wave32) -> target gfx942 / gfx950 (wave64)

Impact

Blocks cross-family HotSwap of real GPU workloads that use __crash__ -- a gfx1250-only
instruction with no direct GFX9 equivalent. A handler (emulation / safe-lowering) or an
explicit refuse-with-note is needed.