Add a kSimd128 machine type for Turbofan.

src/compiler/representation-change.cc

Index: src/compiler/representation-change.cc
diff --git a/src/compiler/representation-change.cc b/src/compiler/representation-change.cc
index 5dab60f6a32bd06a101d7e6e380f184498b7115c..e69b576397b6c550c7578aae18915c0656db9cd8 100644
--- a/src/compiler/representation-change.cc
+++ b/src/compiler/representation-change.cc
@@ -146,6 +146,8 @@ Node* RepresentationChanger::GetRepresentationFor(
       return GetWord32RepresentationFor(node, output_rep, output_type);
     case MachineRepresentation::kWord64:
       return GetWord64RepresentationFor(node, output_rep, output_type);
+    case MachineRepresentation::kSimd128:  // Fall through.
+    // TODO(bbudge) Handle conversions between tagged and untagged.

[Jarin, 2016/02/17 12:06:46]

Until then, could you DCHECK(output_rep == kSimd128)? (Or just "break;" because
we should not try to convert to the same representation.)

[bbudge, 2016/02/17 18:57:14]

break seems right here. Done.

     case MachineRepresentation::kNone:
       return node;
   }