The initialization of static variables that were used originally caused
a data race because multiple threads tried to initialize the variables
at the same time. The use of a LazyInstance guarantees that the
variables get initialized exactly once.

The same problem also existed in c-linkage.cc. There I fixed the problem
by using a local variable instead of a static variable.

BUG=v8:5242
R=titzer@chromium.org

Review-Url: https://codereview.chromium.org/2202433003
Cr-Commit-Position: refs/heads/master@{#38221}