PPC/S390: [es6] Reintroduce the instanceof operator in the backends.

src/s390/interface-descriptors-s390.cc

Index: src/s390/interface-descriptors-s390.cc
diff --git a/src/s390/interface-descriptors-s390.cc b/src/s390/interface-descriptors-s390.cc
index a4cdf553a5272be81165b347b032384f74226e92..aae19494dfec89875f5a12822521946f95b8aa52 100644
--- a/src/s390/interface-descriptors-s390.cc
+++ b/src/s390/interface-descriptors-s390.cc
@@ -36,9 +36,6 @@ const Register LoadGlobalViaContextDescriptor::SlotRegister() { return r4; }
 const Register StoreGlobalViaContextDescriptor::SlotRegister() { return r4; }
 const Register StoreGlobalViaContextDescriptor::ValueRegister() { return r2; }
 
-const Register InstanceOfDescriptor::LeftRegister() { return r3; }
-const Register InstanceOfDescriptor::RightRegister() { return r2; }
-
 const Register StringCompareDescriptor::LeftRegister() { return r3; }
 const Register StringCompareDescriptor::RightRegister() { return r2; }