Revert of [Turbofan] Fix perf regression (patchset #1 id:1 of...

Revert of [Turbofan] Fix perf regression (patchset #1 id:1 of https://codereview.chromium.org/1412123009/ )

Reason for revert:
[sheriff] breaks benchmarks:
http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20debug/builds/4998

Original issue's description:
> [Turbofan] Fix perf regression introduced by per-range change.
>
> When the range ends just at the gap of a non-deferred block, the last
> instruction the range covers is in the predecessor. If that predecessor is
> a deferred block, before this CL, we would splinter the remainder of the
> range all the way to the end. That leads to inefficient codegen, because
> we still want a split inside the deferred block.
>
> Also, opportunistically added a trace before we splinter, for better
> diagnostics.
>
> BUG= chromium:546416
> LOG=N
>
> Committed: https://crrev.com/32b6e085e74a8fcf94a01d20740fe4fdede07a86
> Cr-Commit-Position: refs/heads/master@{#31529}

TBR=bmeurer@chromium.org,jarin@chromium.org,mtrofin@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= chromium:546416

Review URL: https://codereview.chromium.org/1412893007

Cr-Commit-Position: refs/heads/master@{#31531}

src/compiler/live-range-separator.cc

@@ -51,8 +51,6 @@ void CreateSplinter(TopLevelLiveRange *range, RegisterAllocationData *data,
       range->SetSplinter(splinter);
     }
     Zone *zone = data->allocation_zone();
-    TRACE("creating splinter for range %d between %d and %d\n", range->vreg(),
-          start.ToInstructionIndex(), end.ToInstructionIndex());
     range->Splinter(start, end, zone);
   }
 }
@@ -114,9 +112,8 @@ void SplinterLiveRange(TopLevelLiveRange *range, RegisterAllocationData *data) {
     interval = next_interval;
   }
   // When the range ends in deferred blocks, first_cut will be valid here.
-  // Splinter from there to the last instruction that was in a deferred block.
   if (first_cut.IsValid()) {
-    CreateSplinter(range, data, first_cut, last_cut);
+    CreateSplinter(range, data, first_cut, range->End());
   }
 }
 }  // namespace