Make context register implicit for CallInterfaceDescriptors

src/interface-descriptors.h

 // Copyright 2014 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_CALL_INTERFACE_DESCRIPTOR_H_
 #define V8_CALL_INTERFACE_DESCRIPTOR_H_
 
 #include "src/assembler.h"
 #include "src/macro-assembler.h"
 
@@ skipping 122 matching lines @@
 
 
 class CallInterfaceDescriptor {
  public:
   CallInterfaceDescriptor() : data_(NULL) {}
   virtual ~CallInterfaceDescriptor() {}
 
   CallInterfaceDescriptor(Isolate* isolate, CallDescriptors::Key key)
       : data_(isolate->call_descriptor_data(key)) {}
 
-  int GetEnvironmentLength() const { return data()->register_param_count(); }
-
   int GetRegisterParameterCount() const {
     return data()->register_param_count();
   }
 
-  Register GetParameterRegister(int index) const {
+  int GetStackParameterCount() const {
+    return data()->function_type()->Arity() - data()->register_param_count();
+  }
+
+  Register GetRegisterParameter(int index) const {
     return data()->register_param(index);
   }
 
   Type* GetParameterType(int index) const {
     DCHECK(index < data()->register_param_count());
     return data()->register_param_type(index);
   }
 
-  // "Environment" versions of parameter functions. The first register
-  // parameter (context) is not included.
-  int GetEnvironmentParameterCount() const {
-    return GetEnvironmentLength() - 1;
-  }
-
-  Register GetEnvironmentParameterRegister(int index) const {
-    return GetParameterRegister(index + 1);
-  }
-
-  Type* GetEnvironmentParameterType(int index) const {
-    return GetParameterType(index + 1);
-  }
-
   // Some platforms have extra information to associate with the descriptor.
   PlatformInterfaceDescriptor* platform_specific_descriptor() const {
     return data()->platform_specific_descriptor();
   }
 
   Type::FunctionType* GetFunctionType() const {
     return data()->function_type();
   }
 
   static const Register ContextRegister();
@@ skipping 449 matching lines @@
 }  // namespace v8::internal
 
 
 #if V8_TARGET_ARCH_ARM64
 #include "src/arm64/interface-descriptors-arm64.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/arm/interface-descriptors-arm.h"
 #endif
 
 #endif  // V8_CALL_INTERFACE_DESCRIPTOR_H_