None of the dependencies have changed in 1.15. It may be possible to simplify
some of the wrappers in rawfile following 1.13, but that can come in a later
change.
PiperOrigin-RevId: 313863264
* Rename syncutil to sync.
* Add aliases to sync types.
* Replace existing usage of standard library sync package.
This will make it easier to swap out synchronization primitives. For example,
this will allow us to use primitives from github.com/sasha-s/go-deadlock to
check for lock ordering violations.
Updates #1472
PiperOrigin-RevId: 289033387