Revert of [turbofan] Skip printing of empty gap moves. (patchset #1 id:1 of...

Revert of [turbofan] Skip printing of empty gap moves. (patchset #1 id:1 of https://codereview.chromium.org/812983002/)

Reason for revert:
Needed to revert https://chromium.googlesource.com/v8/v8/+/70b5eb47b39acbf31746f4a116a9b3ce2730218a

Original issue's description:
> [turbofan] Skip printing of empty gap moves.
>
> R=bmeurer@chromium.org
> BUG=

TBR=bmeurer@chromium.org,titzer@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/816703002

Cr-Commit-Position: refs/heads/master@{#25886}

src/compiler/instruction.cc

@@ -287,18 +287,16 @@ std::ostream& operator<<(std::ostream& os,
 
   if (instr.IsGapMoves()) {
     const GapInstruction* gap = GapInstruction::cast(&instr);
-    if (!gap->IsRedundant()) {
-      os << "gap ";
-      for (int i = GapInstruction::FIRST_INNER_POSITION;
-           i <= GapInstruction::LAST_INNER_POSITION; i++) {
-        os << "(";
-        if (gap->parallel_moves_[i] != NULL) {
-          PrintableParallelMove ppm = {printable.register_configuration_,
-                                       gap->parallel_moves_[i]};
-          os << ppm;
-        }
-        os << ") ";
+    os << "gap ";
+    for (int i = GapInstruction::FIRST_INNER_POSITION;
+         i <= GapInstruction::LAST_INNER_POSITION; i++) {
+      os << "(";
+      if (gap->parallel_moves_[i] != NULL) {
+        PrintableParallelMove ppm = {printable.register_configuration_,
+                                     gap->parallel_moves_[i]};
+        os << ppm;
       }
+      os << ") ";
     }
   } else if (instr.IsSourcePosition()) {
     const SourcePositionInstruction* pos =