Revert of [regexp] Remove remainder of native RegExpExecStub

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 25707a34aa018a576288a5cb7641b555c1c52ed2..4601e98785175dbecf23a3ac99e70f22bf1135c4 100644
--- a/src/x87/interface-descriptors-x87.cc
+++ b/src/x87/interface-descriptors-x87.cc
@@ -56,6 +56,11 @@
   return MathPowTaggedDescriptor::exponent();
 }
 
+const Register RegExpExecDescriptor::StringRegister() { return eax; }
+const Register RegExpExecDescriptor::LastIndexRegister() { return ecx; }
+const Register RegExpExecDescriptor::StringStartRegister() { return edx; }
+const Register RegExpExecDescriptor::StringEndRegister() { return ebx; }
+const Register RegExpExecDescriptor::CodeRegister() { return edi; }
 
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return eax; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return ebx; }