[llvm] [AArch64] Ensure the type of LDNP/STNP is always v2i64 (PR #150378)

[David Green via llvm-commits]

davemgreen wrote:

Yeah I took that as meaning that it needed a specific type and couldn't decide which. AFAIU the pattern would need to be duplicated per type and just picking one type in SDAG seems OK I think.

https://github.com/llvm/llvm-project/pull/150378