Remove usages of Heap::NewSpaceStart and its external reference

src/heap/spaces.h

 // Copyright 2011 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_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include "src/allocation.h"
 #include "src/atomic-utils.h"
 #include "src/base/atomicops.h"
@@ skipping 2673 matching lines @@
   }
 
   // Return the address of the first object in the active semispace.
   Address bottom() { return to_space_.space_start(); }
 
   // Get the age mark of the inactive semispace.
   Address age_mark() { return from_space_.age_mark(); }
   // Set the age mark in the active semispace.
   void set_age_mark(Address mark) { to_space_.set_age_mark(mark); }
 
-  // The start address of the space and a bit mask. Anding an address in the
-  // new space with the mask will result in the start address.
-  Address start() { return start_; }
-
   // The allocation top and limit address.
   Address* allocation_top_address() { return allocation_info_.top_address(); }
 
   // The allocation limit address.
   Address* allocation_limit_address() {
     return allocation_info_.limit_address();
   }
 
   MUST_USE_RESULT INLINE(AllocationResult AllocateRawAligned(
       int size_in_bytes, AllocationAlignment alignment));
@@ skipping 103 matching lines @@
 
   Address chunk_base_;
   uintptr_t chunk_size_;
 
   // The semispaces.
   SemiSpace to_space_;
   SemiSpace from_space_;
   base::VirtualMemory reservation_;
   int pages_used_;
 
-  // Start address and bit mask for containment testing.
-  Address start_;
-
   // Allocation pointer and limit for normal allocation and allocation during
   // mark-compact collection.
   AllocationInfo allocation_info_;
 
   Address top_on_previous_step_;
 
   HistogramInfo* allocated_histogram_;
   HistogramInfo* promoted_histogram_;
 
   bool EnsureAllocation(int size_in_bytes, AllocationAlignment alignment);
@@ skipping 258 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_