With this CL the out-of-line code of TrapIf will call a builtin instead
of doing a direct runtime call, which is cheaper. In the best case, the
out-of-line code now consists of a single call instruction. The builtin
will load the trapID and then call the runtime to throw a trap.

R=titzer@chromium.org, clemensh@chromium.org

Change-Id: I8a75ba09f40236a3d5cbdc17c1317baf0a3c915a
Reviewed-on: https://chromium-review.googlesource.com/445937
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43366}