Replaced different means of zone pooling/reusing by one zone segment pool

BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/dcheck_always_on.gni")
 import("//build/config/mips.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
@@ skipping 1163 matching lines @@
     "src/compiler/types.cc",
     "src/compiler/types.h",
     "src/compiler/unwinding-info-writer.h",
     "src/compiler/value-numbering-reducer.cc",
     "src/compiler/value-numbering-reducer.h",
     "src/compiler/verifier.cc",
     "src/compiler/verifier.h",
     "src/compiler/wasm-compiler.cc",
     "src/compiler/wasm-compiler.h",
     "src/compiler/wasm-linkage.cc",
-    "src/compiler/zone-pool.cc",
-    "src/compiler/zone-pool.h",
+    "src/compiler/zonestats.cc",
+    "src/compiler/zonestats.h",
     "src/context-measure.cc",
     "src/context-measure.h",
     "src/contexts-inl.h",
     "src/contexts.cc",
     "src/contexts.h",
     "src/conversions-inl.h",
     "src/conversions.cc",
     "src/conversions.h",
     "src/counters-inl.h",
     "src/counters.cc",
@@ skipping 1588 matching lines @@
     ":fuzzer_support",
     ":lib_wasm_section_fuzzer",
     ":wasm_module_runner",
   ]
 
   configs = [ ":internal_config" ]
 }
 
 v8_fuzzer("wasm_data_section_fuzzer") {
 }