X87: [es6] Reintroduce the instanceof operator in the backends.

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 66494f3eda6abf64c9a20c8f21eb2cf158f7028a..260d8716a0f0ad16a5167a9378a2a539d8c1e4c9 100644
--- a/src/x87/interface-descriptors-x87.cc
+++ b/src/x87/interface-descriptors-x87.cc
@@ -51,10 +51,6 @@ const Register StoreGlobalViaContextDescriptor::SlotRegister() { return ebx; }
 const Register StoreGlobalViaContextDescriptor::ValueRegister() { return eax; }
 
 
-const Register InstanceOfDescriptor::LeftRegister() { return edx; }
-const Register InstanceOfDescriptor::RightRegister() { return eax; }
-
-
 const Register StringCompareDescriptor::LeftRegister() { return edx; }
 const Register StringCompareDescriptor::RightRegister() { return eax; }