This fixes a typo where we stored the framepointer in the constant pool
register instead of the constant pool value.

Bug: v8:7915
Change-Id: I612bf1860ed2e5e5707e2df4a2b92aefaaa9c5cb
Reviewed-on: https://chromium-review.googlesource.com/1127639Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54283}