Log Message:
Update Go to 1.8.

The compiler back end introduced in Go 1.7 for 64-bit x86 is now used on all
architectures, and those architectures should see significant performance
improvements. For instance, the CPU time required by our benchmark programs was
reduced by 20-30% on 32-bit ARM systems. There are also some modest performance
improvements in this release for 64-bit x86 systems. The compiler and linker
have been made faster. Compile times should be improved by about 15% over Go
1.7. There is still more work to be done in this area: expect faster
compilation speeds in future releases.

Garbage collection pauses should be significantly shorter, usually under 100
microseconds and often as low as 10 microseconds.

The HTTP server adds support for HTTP/2 Push, allowing servers to preemptively
send responses to a client. This is useful for minimizing network latency by
eliminating roundtrips. The HTTP server also adds support for graceful
shutdown, allowing servers to minimize downtime by shutting down only after
serving all requests that are in flight.

Contexts (added to the standard library in Go 1.7) provide a cancelation and
timeout mechanism. Go 1.8 adds support for contexts in more parts of the
standard library, including the database/sql and net packages and
Server.Shutdown in the net/http package.

Go 1.8 includes many more additions, improvements, and fixes. Find the complete
set of changes, and more information about the improvements listed above, in
the Go 1.8 release notes: https://golang.org/doc/go1.8