[llvm] [TableGen] Rework `EmitIntrinsicToBuiltinMap` (PR #104681)

[Jakub Kuderski via llvm-commits]

kuhar wrote:

>  (@kuhar I assume you meant the changes other than the one adding maximal which this used by this MR. Is that correct?)

I'd also land it separately -- this should make reverting/fixups easier. I'm thinking about scenarios where we have to revert this PR and reland it, which would cause everybody to recompile 90% of the llvm project just because the revert touches STLExtras.h.

https://github.com/llvm/llvm-project/pull/104681