[regexp] Port RegExpExecStub to CSA (mostly)

src/ia32/interface-descriptors-ia32.cc

Index: src/ia32/interface-descriptors-ia32.cc
diff --git a/src/ia32/interface-descriptors-ia32.cc b/src/ia32/interface-descriptors-ia32.cc
index 0264af918d55db683425c94af04ec556e4438dbd..75069aa7cbdc9093446d83bcabf7cea90a9552a6 100644
--- a/src/ia32/interface-descriptors-ia32.cc
+++ b/src/ia32/interface-descriptors-ia32.cc
@@ -52,11 +52,15 @@ const Register ApiGetterDescriptor::CallbackRegister() { return eax; }
 
 const Register MathPowTaggedDescriptor::exponent() { return eax; }
 
-
 const Register MathPowIntegerDescriptor::exponent() {
   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; }