[wasm] Change the constant kV8MaxWasmMemoryPages to a command line flag.

src/wasm/module-decoder.cc

 // Copyright 2015 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.
 
 #include "src/wasm/module-decoder.h"
 
 #include "src/base/functional.h"
 #include "src/base/platform/platform.h"
 #include "src/flags.h"
 #include "src/macro-assembler.h"
@@ skipping 304 matching lines @@
             consume_resizable_limits("element count", "elements",
                                      kV8MaxWasmTableSize, &table->min_size,
                                      &table->has_max, kV8MaxWasmTableSize,
                                      &table->max_size);
             break;
           }
           case kExternalMemory: {
             // ===== Imported memory =========================================
             if (!AddMemory(module)) break;
             consume_resizable_limits(
-                "memory", "pages", kV8MaxWasmMemoryPages,
+                "memory", "pages", FLAG_wasm_max_mem_pages,
                 &module->min_mem_pages, &module->has_max_mem,
                 kSpecMaxWasmMemoryPages, &module->max_mem_pages);
             break;
           }
           case kExternalGlobal: {
             // ===== Imported global =========================================
             import->index = static_cast<uint32_t>(module->globals.size());
             module->globals.push_back(
                 {kWasmStmt, false, WasmInitExpr(), 0, true, false});
             WasmGlobal* global = &module->globals.back();
@@ skipping 51 matching lines @@
       }
       section_iter.advance();
     }
 
     // ===== Memory section ==================================================
     if (section_iter.section_code() == kMemorySectionCode) {
       uint32_t memory_count = consume_count("memory count", kV8MaxWasmMemories);
 
       for (uint32_t i = 0; ok() && i < memory_count; i++) {
         if (!AddMemory(module)) break;
-        consume_resizable_limits("memory", "pages", kV8MaxWasmMemoryPages,
+        consume_resizable_limits("memory", "pages", FLAG_wasm_max_mem_pages,
                                  &module->min_mem_pages, &module->has_max_mem,
                                  kSpecMaxWasmMemoryPages,
                                  &module->max_mem_pages);
       }
       section_iter.advance();
     }
 
     // ===== Global section ==================================================
     if (section_iter.section_code() == kGlobalSectionCode) {
       uint32_t globals_count =
@@ skipping 848 matching lines @@
     table.push_back(std::move(func_asm_offsets));
   }
   if (decoder.more()) decoder.error("unexpected additional bytes");
 
   return decoder.toResult(std::move(table));
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8