[llvm] [mlir] Reland "[mlir][spirv] Fix int type declaration duplication when serializing" (PR #145687)

[Davide Grohmann via llvm-commits]

davidegrohmann wrote:

> Please update the PR description message to include info about all the reverted PRs and the revert PR itself.

Updated the description message. Could you check if this is what you were asking for?

https://github.com/llvm/llvm-project/pull/145687