const golang.org/x/sys/unix.SYS_PSYNCH_RW_UPGRADE
one use
golang.org/x/sys/unix (current package)
zsysnum_darwin_arm64.go#L224: SYS_PSYNCH_RW_UPGRADE = 300
The pages are generated with Golds v0.2.8-preview. (GOOS=darwin GOARCH=arm64)