```
hpb::Arena arena;
auto foo = hpb::CreateMessage<Foo>(arena);
foo.GetInternalArena(); // this call will now be impossible
```
Before this CL, any Proxy/Ptr could get its internal arena. This
unnecessarily leaks upb internals when they should be
interacted with via hpb::interop::upb::*.
PiperOrigin-RevId: 676038573
This also increases compliance by adding `default_applicable_licenses` to several `BUILD` files that previously did not have it.
PiperOrigin-RevId: 670784686
This CL is mostly a no-op, except that now google3-only code is actually stripped from OSS, instead of being preserved in `# begin:google_only` blocks.
This follows the conventions of the greater Copybara ecosystem.
PiperOrigin-RevId: 669513564
This simplifies upb by removing differences between google3 and OSS.
This also points upb at the protobuf license, instead of keeping a separate copy around for upb.
PiperOrigin-RevId: 669447145
Hong Shin
Joshua Haberman