[llvm] [LLVM][IR] Replace `unsigned >= ConstantDataFirstVal` with static_assert (PR #140827)

[Rahul Joshi via llvm-commits]

jurahul wrote:

This caused build failures for our downstream build that had warning-as-error enabled. Particularly https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-4-c4296?view=msvc-170


https://github.com/llvm/llvm-project/pull/140827