Remove circular dependencies that were bouncing back and forth between
msg_internal.h and mini_table/, including:
- splitting out each mini table subtype into its own header
- moving the non-reflection message code into message/
- moving the accessors from mini_table/ to message/
PiperOrigin-RevId: 489121042
This is a naming change only, with no functional change. We did replace one inline function that had only one caller, but the net effect should be a no-op.
I did remove several `return` statements for calls to certain `noreturn` functions. These had no effect but were intended to improve readability. However the unused "return" caused ClangTidy to throw warnings, so these have been removed.
PiperOrigin-RevId: 472619191
some headers were not including port_def.inc
some headers were not declaring extern "C"
some headers were backing out of the above in the wrong order
PiperOrigin-RevId: 457391878