[llvm] [SelectionDAG] Add expansion for llvm.convert.to.arbitrary.fp (PR #193595)

[Dmitry Sidorov via llvm-commits]

MrSidims wrote:

> E2E testing on X86 done with an assistance of Claude Code Opus 4.6.

See: https://github.com/MrSidims/llvm-project/tree/only-for-testing-ocl-fp (it doesn't cover all the cases yet just some PoC)

https://github.com/llvm/llvm-project/pull/193595