Add support for aligned loads and stores

[DCNick3]

Is your feature request related to a problem? Please describe. I want to be able to do loads and stores using unaligned pointers on platforms like ARM. Sometimes it requires special code generation, so it's nice to supply LLVM with this info

Describe the solution you'd like Versions of build_store and build_load accepting an alignment argument

Describe possible drawbacks to your solution Can't see any

Describe alternatives you've considered It may be overcame with memcpy shenanigans, but is clearly suboptimal

[nlewycky]

Is it enough to use https://thedan64.github.io/inkwell/inkwell/values/struct.InstructionValue.html#method.set_alignment ?