This is going to guard against regressions when symbol table init is
optimized.

TEST=angle_unittests
BUG=angleproject:2267

Change-Id: Iec7b9814f4af215dc0b3e8a39c8cfab004451836
Reviewed-on: https://chromium-review.googlesource.com/931883Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>