[llvm] [LV] Add support for speculative loads in loops that may fault (PR #151300)

[David Sherwood via llvm-commits]

david-arm wrote:

I think it would be good for reviewers if this patch was split up into several parts, probably roughly in this order:
1. Codegen specific parts related to the RISCV intrinsic,
2. A standalone loop vectorisation legality patch similar to https://github.com/llvm/llvm-project/pull/145663,
3. A loop vectoriser patch that starts vectorising the loops you're interested in.

https://github.com/llvm/llvm-project/pull/151300