X87: Optimize the typeof operator.

src/x87/interface-descriptors-x87.cc

Index: src/x87/interface-descriptors-x87.cc
diff --git a/src/x87/interface-descriptors-x87.cc b/src/x87/interface-descriptors-x87.cc
index 8a6b55e2d36abe6e8aed0e267c919ad3c6345265..515d56c659d2db936f868c91ef4641c93f8311f2 100644
--- a/src/x87/interface-descriptors-x87.cc
+++ b/src/x87/interface-descriptors-x87.cc
@@ -86,6 +86,12 @@ void NumberToStringDescriptor::Initialize(CallInterfaceDescriptorData* data) {
 }
 
 
+void TypeofDescriptor::Initialize(CallInterfaceDescriptorData* data) {
+  Register registers[] = {esi, ebx};
+  data->Initialize(arraysize(registers), registers, NULL);
+}
+
+
 void FastCloneShallowArrayDescriptor::Initialize(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {esi, eax, ebx, ecx};