Unboxed Float64x2 fields and some misc fixes

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
diff --git a/runtime/vm/intermediate_language.cc b/runtime/vm/intermediate_language.cc
index cf8301fc1ac56c2e4be255d8306840ef2c2c5459..f61fb36016d43b92a6dcf5a0003f98bd17d5d6ec 100644
--- a/runtime/vm/intermediate_language.cc
+++ b/runtime/vm/intermediate_language.cc
@@ -162,6 +162,8 @@ Representation LoadFieldInstr::representation() const {
         return kUnboxedDouble;
       case kFloat32x4Cid:
         return kUnboxedFloat32x4;
+      case kFloat64x2Cid:
+        return kUnboxedFloat64x2;
       default:
         UNREACHABLE();
     }
@@ -194,6 +196,8 @@ Representation StoreInstanceFieldInstr::RequiredInputRepresentation(
         return kUnboxedDouble;
       case kFloat32x4Cid:
         return kUnboxedFloat32x4;
+      case kFloat64x2Cid:
+        return kUnboxedFloat64x2;
       default:
         UNREACHABLE();
     }