Revert of [regexp] Remove remainder of native RegExpExecStub

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 04ecff5fbbc6315656dfb299ac95c337dd1ea8ff..dd03f19cbc1cd5db60803178944f4ca0d8140fec 100644
--- a/src/x64/interface-descriptors-x64.cc
+++ b/src/x64/interface-descriptors-x64.cc
@@ -56,6 +56,11 @@
   return MathPowTaggedDescriptor::exponent();
 }
 
+const Register RegExpExecDescriptor::StringRegister() { return arg_reg_1; }
+const Register RegExpExecDescriptor::LastIndexRegister() { return r11; }
+const Register RegExpExecDescriptor::StringStartRegister() { return arg_reg_3; }
+const Register RegExpExecDescriptor::StringEndRegister() { return arg_reg_4; }
+const Register RegExpExecDescriptor::CodeRegister() { return rax; }
 
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return rax; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return rbx; }