Optimize the typeof operator.

src/mips64/interface-descriptors-mips64.cc

Index: src/mips64/interface-descriptors-mips64.cc
diff --git a/src/mips64/interface-descriptors-mips64.cc b/src/mips64/interface-descriptors-mips64.cc
index 50ad745eac8e568b358b24bcf8d1a56e0d36ba78..2d6cabeb0ba34e23056174d721591f3f58110cea 100644
--- a/src/mips64/interface-descriptors-mips64.cc
+++ b/src/mips64/interface-descriptors-mips64.cc
@@ -83,6 +83,12 @@ void NumberToStringDescriptor::Initialize(CallInterfaceDescriptorData* data) {
 }
 
 
+void TypeofDescriptor::Initialize(CallInterfaceDescriptorData* data) {
+  Register registers[] = {cp, a3};
+  data->Initialize(arraysize(registers), registers, NULL);
+}
+
+
 void FastCloneShallowArrayDescriptor::Initialize(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {cp, a3, a2, a1};