Revert "[turbofan] Prettify a condition"

This reverts commit f44900d2.

Reason for revert: caused performance regressions on Nexus 7!?
https://bugs.chromium.org/p/chromium/issues/detail?id=1105420

Original change's description:
> [turbofan] Prettify a condition
>
> Change-Id: I3800486f18a3693c9e2d3ace0a6f8ee626efc84e
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2289780
> Commit-Queue: Georg Neis <neis@chromium.org>
> Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
> Auto-Submit: Georg Neis <neis@chromium.org>
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68756}

TBR=neis@chromium.org,nicohartmann@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: chromium:1105420
Change-Id: Icc97c7c2fff79bb4860a9c36f6d2d3f531e524b5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2310250
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68969}

src/compiler/backend/jump-threading.cc

@@ -206,7 +206,7 @@ void JumpThreading::ApplyForwarding(Zone* local_zone,
     if (constant.type() == Constant::kRpoNumber) {
       RpoNumber rpo = constant.ToRpoNumber();
       RpoNumber fw = result[rpo.ToInt()];
-      if (fw != rpo) immediates[i] = Constant(fw);
+      if (!(fw == rpo)) immediates[i] = Constant(fw);
     }
   }