Imports can also have associated names, and in fact we generate these
names for asm.js. Thus in logging, just append this name to the
generated signature.

R=jkummerow@chromium.org

Bug: chromium:1030103
Change-Id: I3969bcf8d1d17f4256b5a0643acdf8a24766f889
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1948705
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65321}