[llvm] [SandboxIR][NFC] Fixes for LoadInst::create functions (PR #100955)

[Julius Alexandre via llvm-commits]

medievalghoul wrote:

> Btw isVolatile is also missing from StoreInst, so feel free to update that as well.

StoreInst: https://github.com/llvm/llvm-project/pull/100961 (btw, I have to add similar changes to the ones you discussed here onto the StoreInst PR. Mainly the test.) 

@vporpo if it's okay with you, I needed help with understanding why the bot checks were failing for the StoreInst PR I created. if you have time are you able to check it out for me?

https://github.com/llvm/llvm-project/pull/100955