* Fix mutability bug in Java proto lite: sub-messages inside of oneofs were not
being set as immutable. This would allow code to get a builder for a
sub-message and modify the original (supposedly immutable) copy.
GCC cannot infer that `LogMessage::Finish()` (called indirectly by
`GOOGLE_LOG(FAIL)` in `AlignFail`) exits program when `level_ ==
LOGLEVEL_FATAL`. Compilation will create a warning in projects importing
the library for debug builds. The attribute cannot be individually
assigned to `LogMessage::Finish()` because it does return conditionally
of the log level. Tried with GCC 9.3.0 and GCC 12.1.0.
This change adds an explicit abort() for compiler to clearly understand
this does not return, and enables `[[noreturn]]` for MSVC as well.
