tree c75fede3e4679cad28d330f733bfebd1a665b83b
parent 70ba73e6b13c3922d14156e3fc0561e1cbe2b89c
author Derek Mauro <dmauro@google.com> 1741375133 -0800
committer Copybara-Service <copybara-worker@google.com> 1741375177 -0800

bits.h: Add absl::endian and absl::byteswap polyfills

I had to remove the MSVC implementation since it is
not constexpr.
https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/byteswap-uint64-byteswap-ulong-byteswap-ushort?view=msvc-170

But all major compilers understand the portable implementation
is just a bswap: https://godbolt.org/z/oMnW3xsns

Closes #1198

PiperOrigin-RevId: 734626285
Change-Id: Ibca79f408f225c894f3c2b95f7086f891627db9f