Revert of Pool implementation for zone segments

src/v8.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 1261 matching lines @@
         'wasm/wasm-opcodes.cc',
         'wasm/wasm-opcodes.h',
         'wasm/wasm-result.cc',
         'wasm/wasm-result.h',
         'zone/accounting-allocator.cc',
         'zone/accounting-allocator.h',
         'zone/zone-segment.cc',
         'zone/zone-segment.h',
         'zone/zone.cc',
         'zone/zone.h',
-        'zone/zone-segment.cc',
-        'zone/zone-segment.h',
         'zone/zone-allocator.h',
         'zone/zone-containers.h',
       ],
       'conditions': [
         ['want_separate_host_toolset==1', {
           'toolsets': ['host', 'target'],
         }, {
           'toolsets': ['target'],
         }],
         ['want_separate_host_toolset_mkpeephole==1', {
@@ skipping 1149 matching lines @@
       'conditions': [
         ['want_separate_host_toolset_mkpeephole==1', {
           'toolsets': ['host'],
         }, {
           'toolsets': ['target'],
         }],
       ],
     },
   ],
 }