Revert of Remove SIMD.js from V8.

src/profiler/heap-snapshot-generator.cc

Index: src/profiler/heap-snapshot-generator.cc
diff --git a/src/profiler/heap-snapshot-generator.cc b/src/profiler/heap-snapshot-generator.cc
index ddce12e37c0e36074c91037d72072a2711ae5b72..108504bb40bf1a697b507f8fc721ad9d370d8f9f 100644
--- a/src/profiler/heap-snapshot-generator.cc
+++ b/src/profiler/heap-snapshot-generator.cc
@@ -154,6 +154,7 @@
     case kConsString: return "/concatenated string/";
     case kSlicedString: return "/sliced string/";
     case kSymbol: return "/symbol/";
+    case kSimdValue: return "/simd/";
     default: return "???";
   }
 }
@@ -837,6 +838,8 @@
     return AddEntry(object, HeapEntry::kArray, "");
   } else if (object->IsHeapNumber()) {
     return AddEntry(object, HeapEntry::kHeapNumber, "number");
+  } else if (object->IsSimd128Value()) {
+    return AddEntry(object, HeapEntry::kSimdValue, "simd");
   }
   return AddEntry(object, HeapEntry::kHidden, GetSystemEntryName(object));
 }