[regexp] Add slow exec stub to reduce code size

src/interface-descriptors.h

Index: src/interface-descriptors.h
diff --git a/src/interface-descriptors.h b/src/interface-descriptors.h
index c31838661f1e9ec06a19965550c301c5bd03c6d3..c6676291a9245eb56a6de3c9e72bc92039d0b894 100644
--- a/src/interface-descriptors.h
+++ b/src/interface-descriptors.h
@@ -49,6 +49,7 @@ class PlatformInterfaceDescriptor;
   V(CallTrampoline)                       \
   V(ConstructStub)                        \
   V(ConstructTrampoline)                  \
+  V(GenericTagged2)                       \
   V(RegExpExec)                           \
   V(RegExpReplace)                        \
   V(RegExpSplit)                          \
@@ -645,6 +646,13 @@ class CallConstructDescriptor : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(CallConstructDescriptor, CallInterfaceDescriptor)
 };
 
+class GenericTagged2Descriptor : public CallInterfaceDescriptor {
+ public:
+  DEFINE_PARAMETERS(kFirst, kSecond)
+  DECLARE_DEFAULT_DESCRIPTOR(GenericTagged2Descriptor, CallInterfaceDescriptor,
+                             kParameterCount)
+};
+
 class RegExpExecDescriptor : public CallInterfaceDescriptor {
  public:
   DEFINE_PARAMETERS(kString, kLastIndex, kStringStart, kStringEnd, kCode)