[libc-commits] [libc] [llvm] [reland][libc] Remove UB specializations of type traits for `BigInt` (PR #84299)

[Guillaume Chatelet via libc-commits]

gchatelet wrote:

@legrosbuffle fixup are added as separate commits on top of cherry-picking the defective patch.

https://github.com/llvm/llvm-project/pull/84299