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

[Sergei Barannikov via llvm-commits]

s-barannikov wrote:

I thought `SDTCisVec<>` would work, but I got a bunch of errors and an assertion failure in TableGen.
It's still a mystery to me what works and what doesn't.


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