The test requires tons of memory and results various failures, mainly
runtime errors and process termination by SIGKILL, caused by resource
exhaustion when the node under test doesn't have much resources.

This change makes use of -tcpbig flag to enable the test.

Change-Id: Id53fa5d88543e2e60ca9bb4f55a1914ccca844e1
Reviewed-on: https://go-review.googlesource.com/33254Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>