Revert "Create a RegisterSpec class inside of the IC that provides:"

src/code-stubs.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
@@ skipping 257 matching lines @@
 
 struct CodeStubInterfaceDescriptor {
   CodeStubInterfaceDescriptor();
   int register_param_count_;
 
   Register stack_parameter_count_;
   // if hint_stack_parameter_count_ > 0, the code stub can optimize the
   // return sequence. Default value is -1, which means it is ignored.
   int hint_stack_parameter_count_;
   StubFunctionMode function_mode_;
-  const Register* register_params_;
+  Register* register_params_;
   // Specifies Representations for the stub's parameter. Points to an array of
   // Representations of the same length of the numbers of parameters to the
   // stub, or if NULL (the default value), Representation of each parameter
   // assumed to be Tagged()
   Representation* register_param_representations_;
 
   Address deoptimization_handler_;
   HandlerArgumentsMode handler_arguments_mode_;
 
   bool initialized() const { return register_param_count_ >= 0; }
@@ skipping 2194 matching lines @@
 
 
 class CallDescriptors {
  public:
   static void InitializeForIsolate(Isolate* isolate);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_