[Interpreter] Introduce IncStub and DecStub.

src/interface-descriptors.h

Index: src/interface-descriptors.h
diff --git a/src/interface-descriptors.h b/src/interface-descriptors.h
index 378f0ce6f907f5fb4e5dee4f39f2128ce4e9f7bc..c3bf20c0a76634089b560338a4cd7402d53b0a8b 100644
--- a/src/interface-descriptors.h
+++ b/src/interface-descriptors.h
@@ -66,6 +66,7 @@ class PlatformInterfaceDescriptor;
   V(Compare)                                  \
   V(BinaryOp)                                 \
   V(BinaryOpWithAllocationSite)               \
+  V(CountOp)                                  \
   V(StringAdd)                                \
   V(StringCompare)                            \
   V(Keyed)                                    \
@@ -631,6 +632,10 @@ class BinaryOpWithAllocationSiteDescriptor : public CallInterfaceDescriptor {
                      CallInterfaceDescriptor)
 };
 
+class CountOpDescriptor final : public CallInterfaceDescriptor {
+ public:
+  DECLARE_DESCRIPTOR(CountOpDescriptor, CallInterfaceDescriptor)
+};
 
 class StringAddDescriptor : public CallInterfaceDescriptor {
  public: