Integrate from Piper for C++, Java, and Python

[mkruskal-google]

Important: this integration must be merged, not squashed!

[nickdesaulniers]

Did this PR introduce a different ABI between sanitized and non-sanitized builds?

Trying to upgrade from ancient versions to 22.5 (my bisection landed on this merge commit), I hit an issue:

<path>/usr/lib/clang/20/include/emmintrin.h:3462:47: runtime error: member access within null pointer of type 'const struct __loadu_si128'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior <path>usr/lib/clang/20/include/emmintrin.h:3462:47

Turns out, we were building protobuf with -fno-sanitize=all, but then (accidentally) linking against object files compiled with -fsanitized=undefined (bad, don't do that). Turns out, absl also has different ABIs, which was also a recent problem for us.
abseil/abseil-cpp#1979

Simply not setting -fno-sanitize=all when building protobuf (when linking against object files built with -fsanitize=*) was my solution. Adding this note in case search engines help someone else track down similar failures in the future.