When checking {const char*} (or similar) against each other, don't
print them as c strings on failure. Just print the pointer value.
In wasm, where we use byte pointers into wasm wire bytes, this was
sometimes hiding check failures behind segfaults which happened when
trying to output invalid pointers as c strings.
Anyway, it's more useful to see the raw pointer values in these cases.
Other use cases, where we really compare against c string pointers
should be rare in our code base.

R=ishell@chromium.org

Change-Id: I92a13221d18c987a97cf2a29ac8f454178ff2bb5
Reviewed-on: https://chromium-review.googlesource.com/517166
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45642}