Correctify instanceof and make it optimizable.

src/x64/interface-descriptors-x64.cc

Index: src/x64/interface-descriptors-x64.cc
diff --git a/src/x64/interface-descriptors-x64.cc b/src/x64/interface-descriptors-x64.cc
index 0911254f72095165bda1aaaa48ae369cb8157ea8..4532da271b25814ce27831eeeda8e9c235c465c7 100644
--- a/src/x64/interface-descriptors-x64.cc
+++ b/src/x64/interface-descriptors-x64.cc
@@ -46,8 +46,8 @@ const Register StoreGlobalViaContextDescriptor::SlotRegister() { return rbx; }
 const Register StoreGlobalViaContextDescriptor::ValueRegister() { return rax; }
 
 
-const Register InstanceofDescriptor::left() { return rax; }
-const Register InstanceofDescriptor::right() { return rdx; }
+const Register InstanceOfDescriptor::LeftRegister() { return rdx; }
+const Register InstanceOfDescriptor::RightRegister() { return rax; }
 
 
 const Register ArgumentsAccessReadDescriptor::index() { return rdx; }