[llvm] [SandboxIR] Implement Instruction flags (PR #103343)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

actually, I think the `Instruction` version of some of these methods are not widely used, only the `FPMathOperator` versions. we might be able to do some cleanup and remove these from `Instruction`

https://github.com/llvm/llvm-project/pull/103343