[Interpreter] Make InterpreterAssembler a subclass of CodeStubAssembler.

src/compiler/linkage.h

Index: src/compiler/linkage.h
diff --git a/src/compiler/linkage.h b/src/compiler/linkage.h
index 564f779e9b5b9f601233e36ec71d7a1f799afb9d..2d30545ec0d2eb301f6cffd91d82d519340861b1 100644
--- a/src/compiler/linkage.h
+++ b/src/compiler/linkage.h
@@ -336,11 +336,6 @@ class Linkage : public ZoneObject {
       Zone* zone, const MachineSignature* sig,
       bool set_initialize_root_flag = false);
 
-  // Creates a call descriptor for interpreter handler code stubs. These are not
-  // intended to be called directly but are instead dispatched to by the
-  // interpreter.
-  static CallDescriptor* GetInterpreterDispatchDescriptor(Zone* zone);
-
   // Get the location of an (incoming) parameter to this function.
   LinkageLocation GetParameterLocation(int index) const {
     return incoming_->GetInputLocation(index + 1);  // + 1 to skip target.
@@ -390,15 +385,6 @@ class Linkage : public ZoneObject {
   // A special {OsrValue} index to indicate the context spill slot.
   static const int kOsrContextSpillSlotIndex = -1;
 
-  // Special parameter indices used to pass fixed register data through
-  // interpreter dispatches.
-  static const int kInterpreterAccumulatorParameter = 0;
-  static const int kInterpreterRegisterFileParameter = 1;
-  static const int kInterpreterBytecodeOffsetParameter = 2;
-  static const int kInterpreterBytecodeArrayParameter = 3;
-  static const int kInterpreterDispatchTableParameter = 4;
-  static const int kInterpreterContextParameter = 5;
-
  private:
   CallDescriptor* const incoming_;