[llvm] [SandboxIR] Implement AddrSpaceCastInst (PR #101260)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

You got approval for upstreaming SandboxIR. Your team opens PR, reviews, accepts, and merges them. You might promote somebody from your team to code owner.

https://github.com/llvm/llvm-project/pull/101260