[llvm] [AArch64][GlobalISel] Adopt some Ld* patterns to reduce codegen regressions (PR #135492)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> If I understood everything correctly, this commit fixes the type of a scalar inserted into a vector, not the index type. `i8` in Ld1Lane64Pat definition from this commit is responsible for the STy parameter:
> 

Same principle applies. I expect to see legal types (in the DAG legal sense). The MIR the selector sees has the same type signature as the DAG node, shouldn't require adjusting the patterns but the input legalization 

https://github.com/llvm/llvm-project/pull/135492