This reverts commit 9cd33e9e.

Reason for revert: Didn't add value.

Original change's description:
> [build] Temporarily make ubsan bot use no snapshot
> 
> Currently mksnapshot fails due to ubsan issues. With a nosnap build it
> will be easier to track down failures initially as normal test
> failures, since mksnapshot isn't called with the sanitizer
> environment variables.
> 
> NOTRY=true
> TBR=jgruber@chromium.org
> 
> Bug: v8:7860
> Change-Id: I897a8d307d90f545c80a90e1e1a2a632ffae1c3e
> Reviewed-on: https://chromium-review.googlesource.com/1116783
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54051}

TBR=machenbach@chromium.org,jgruber@chromium.org

Change-Id: I31e06fafb845c07bbaeb7a104d130f923d3be062
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7860
Reviewed-on: https://chromium-review.googlesource.com/1118039Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54075}