[llvm] [SandboxIR] Add more Instruction member functions (PR #98588)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

rst is the default. There is no markdown.
https://github.com/llvm/llvm-project/blob/main/llvm/docs/SphinxQuickstartTemplate.rst

https://github.com/llvm/llvm-project/pull/98588