```
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
Migrate ::hpb::internal::GetMiniTable to ::hpb::interop::upb::GetMiniTable
hpb.h now shows signs of backend-awareness, #including upb.h if the backend is known to be upb. If no backend is picked, we error out at this time since we solely support upb.
ClearMessage has been migrated to backend-aware hpb.
PiperOrigin-RevId: 665527832