Instead of having both a templatized and a parameter-based method, just
have the parameter-based one, but make it constexpr. DCHECKs in these
constexpr methods need to be guarded because GCC 5 does not support them
yet.

R=thibaudm@chromium.org

Bug: v8:10021
Change-Id: If362de42f1a4c2cda4435fce63beb9244795d008
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1986001Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65611}