[turbofan] Initial version of allocation folding and write barrier elimination.

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 29 matching lines @@
   V(CallFunction)                             \
   V(CallFunctionWithFeedback)                 \
   V(CallFunctionWithFeedbackAndVector)        \
   V(CallConstruct)                            \
   V(CallTrampoline)                           \
   V(ConstructStub)                            \
   V(ConstructTrampoline)                      \
   V(RegExpConstructResult)                    \
   V(TransitionElementsKind)                   \
   V(AllocateHeapNumber)                       \
-  V(AllocateMutableHeapNumber)                \
   V(AllocateFloat32x4)                        \
   V(AllocateInt32x4)                          \
   V(AllocateUint32x4)                         \
   V(AllocateBool32x4)                         \
   V(AllocateInt16x8)                          \
   V(AllocateUint16x8)                         \
   V(AllocateBool16x8)                         \
   V(AllocateInt8x16)                          \
   V(AllocateUint8x16)                         \
   V(AllocateBool8x16)                         \
@@ skipping 514 matching lines @@
 };
 
 #define SIMD128_ALLOC_DESC(TYPE, Type, type, lane_count, lane_type)         \
   class Allocate##Type##Descriptor : public CallInterfaceDescriptor {       \
    public:                                                                  \
     DECLARE_DESCRIPTOR(Allocate##Type##Descriptor, CallInterfaceDescriptor) \
   };
 SIMD128_TYPES(SIMD128_ALLOC_DESC)
 #undef SIMD128_ALLOC_DESC
 
-class AllocateMutableHeapNumberDescriptor : public CallInterfaceDescriptor {
- public:
-  DECLARE_DESCRIPTOR(AllocateMutableHeapNumberDescriptor,
-                     CallInterfaceDescriptor)
-};
-
 class ArrayNoArgumentConstructorDescriptor : public CallInterfaceDescriptor {
  public:
   DECLARE_DESCRIPTOR_WITH_CUSTOM_FUNCTION_TYPE(
       ArrayNoArgumentConstructorDescriptor, CallInterfaceDescriptor)
   enum ParameterIndices {
     kFunctionIndex,
     kAllocationSiteIndex,
     kArgumentCountIndex,
     kContextIndex
   };
@@ skipping 261 matching lines @@
 }  // namespace v8
 
 
 #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_