Remove TautologicalInRangeCompare from Extra and TautologicalCompare.
This removes the following (already default-off) warnings from -Wextra:
-Wtautological-type-limit-compare, -Wtautological-unsigned-zero-compare -Wtautological-unsigned-enum-zero-compare
On the thread "[cfe-dev] -Wtautological-constant-compare issues", clang
code owners Richard Smith, John McCall, and Reid Kleckner as well as
libc++ code owner Marshall Clow stated that these new warnings are not
yet ready for prime time and shouldn't be part of -Wextra.
Furthermore, Vedant Kumar (Apple), Peter Hosek (Fuchsia), and me (Chromium)
expressed the same concerns (Vedant on that thread, Peter on
https://reviews.llvm.org/D39462, me on https://reviews.llvm.org/D41512).
So remove them from -Wextra, and remove TautologicalInRangeCompare from
TautologicalCompare too until they're usable with real-world code.