This is to easier diagnose build issues involving the snapshot.
Sample error message for mismatching snapshot:

#
# Fatal error in ../../src/snapshot/snapshot-common.cc, line 286
# Version mismatch between V8 binary and snapshot.
#   V8 binary version: 6.3.1 (candidate)
#    Snapshot version: 6.3.0 (candidate)
# The snapshot consists of 2820444 bytes and contains 1 contexts.
#


R=machenbach@chromium.org

Bug: chromium:764327
Change-Id: Icdc7aeac77819b113985b424feda814a072d5406
Reviewed-on: https://chromium-review.googlesource.com/684295Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48161}