Inline simple setter calls.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 6bf803c54bf8086bff44a4a384a82b0acd54145f..d34436b93433d3cd01ec4ee8cc1e19e5ceb48149 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -380,11 +380,12 @@ void LCodeGen::WriteTranslation(LEnvironment* environment,
     case JS_CONSTRUCT:
       translation->BeginConstructStubFrame(closure_id, translation_size);
       break;
+    case JS_SETTER:
+      // TODO(svenpanne) Implement me!
+      break;
     case ARGUMENTS_ADAPTOR:
       translation->BeginArgumentsAdaptorFrame(closure_id, translation_size);
       break;
-    default:
-      UNREACHABLE();
   }
   for (int i = 0; i < translation_size; ++i) {
     LOperand* value = environment->values()->at(i);