Fix Windows 32.

TBR=dcarney@chromium.org
BUG=

Review URL: https://codereview.chromium.org/755323007

Cr-Commit-Position: refs/heads/master@{#25522}

src/compiler/jump-threading.cc

@@ -112,10 +112,13 @@ bool JumpThreading::ComputeForwarding(Zone* local_zone,
     }
   }
 
-#if DEBUG
-  for (RpoNumber num : result) DCHECK(num.IsValid());
+#ifdef DEBUG
+  for (RpoNumber num : result) {
+    CHECK(num.IsValid());
+  }
 #endif
 
+  if (FLAG_trace_turbo_jt) {
     for (int i = 0; i < static_cast<int>(result.size()); i++) {
       TRACE(("RPO%d B%d ", i,
              code->InstructionBlockAt(RpoNumber::FromInt(i))->id().ToInt()));
@@ -127,6 +130,7 @@ bool JumpThreading::ComputeForwarding(Zone* local_zone,
         TRACE(("\n"));
       }
     }
+  }
 
   return state.forwarded;
 }