[clang] [CIR] Handle proper hoisting of const variables with InvariantGroupOp (PR #175037)

[Sirui Mu via cfe-commits]

Lancern wrote:

> The inliner should either be inserting a call to llvm.launder.invariant.group() or removing the metadata, but it doesn't (though it does insert lifetime start/end markers).

Is this intended or is it an LLVM bug? We might contact an LLVM guy to ensure this.

https://github.com/llvm/llvm-project/pull/175037