[LLVM][InstCombine][AArch64] Refactor common SVE intrinsic combines. (#126928)

Introduce SVEIntrinsicInfo to store properties common across SVE
intrinsics. This allows a seperation between intrinsic IDs and the
transformations that can be applied to them, which reduces the layering
problems we hit when adding new combines.

This PR is mostly refactoring to bring in the concept and port the most
common combines (e.g. dead code when all false). This will be followed
up with new combines where I plan to reuse much of the existing
instruction simplifcation logic to significantly improve our ability to
constant fold SVE intrinsics.

Author: paulwalker-arm