Log Message:
Update go116 to 1.16.4.

go1.16.3 (released 2021/04/01) includes fixes to the compiler, linker, runtime,
the go command, and the testing and time packages. See the Go 1.16.3 milestone
on our issue tracker for details.

go1.16.4 (released 2021/05/06) includes a security fix to the net/http package,
as well as bug fixes to the runtime, the compiler, and the archive/zip, time,
and syscall packages. See the Go 1.16.4 milestone on our issue tracker for
details.