While investigating crbug.com/878742 I found that somehow the
MachineOperatorReducer lacks the ability to constant-fold
comparisons of Float64 constants, which obviously leads to
pretty weird code.

Bug: v8:8015
Change-Id: I7e18ce10e9d5c87f131fb083ccd3e1e336189dae
Reviewed-on: https://chromium-review.googlesource.com/1226132Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55935}