[llvm] [NFC][SPIR-V] Add constrainSelectedInstRegOperands helper to dedup repeating pattern in global registry (PR #208703)

[Juan Manuel Martinez Caamaño via llvm-commits]

jmmartinez wrote:

> Switched to MIB.constrainAllUses
> 
> As for global replacement across backends, I'll take a look at this

Wait, what replacement across backends ?

https://github.com/llvm/llvm-project/pull/208703