Revert of [wasm] Increase WebAssembly.Memory maximum size to ~2GB

src/wasm/wasm-limits.h

 // Copyright 2016 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_WASM_WASM_LIMITS_H_
 #define V8_WASM_WASM_LIMITS_H_
 
 #include <cstddef>
 #include <cstdint>
 #include <limits>
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
 // The following limits are imposed by V8 on WebAssembly modules.
 // The limits are agreed upon with other engines for consistency.
 constexpr size_t kV8MaxWasmTypes = 1000000;
 constexpr size_t kV8MaxWasmFunctions = 1000000;
 constexpr size_t kV8MaxWasmImports = 100000;
 constexpr size_t kV8MaxWasmExports = 100000;
 constexpr size_t kV8MaxWasmGlobals = 1000000;
 constexpr size_t kV8MaxWasmDataSegments = 100000;
 // Don't use this limit directly, but use the value of FLAG_wasm_max_mem_pages.
-// Current limit mimics the maximum allowed allocation on an ArrayBuffer
-// (2GiB - 1 page).
-constexpr size_t kV8MaxWasmMemoryPages = 32767;  // ~ 2 GiB
+constexpr size_t kV8MaxWasmMemoryPages = 16384;  // = 1 GiB
 constexpr size_t kV8MaxWasmStringSize = 100000;
 constexpr size_t kV8MaxWasmModuleSize = 1024 * 1024 * 1024;  // = 1 GiB
 constexpr size_t kV8MaxWasmFunctionSize = 128 * 1024;
 constexpr size_t kV8MaxWasmFunctionLocals = 50000;
 constexpr size_t kV8MaxWasmFunctionParams = 1000;
 constexpr size_t kV8MaxWasmFunctionMultiReturns = 1000;
 constexpr size_t kV8MaxWasmFunctionReturns = 1;
 // Don't use this limit directly, but use the value of FLAG_wasm_max_table_size.
 constexpr size_t kV8MaxWasmTableSize = 10000000;
 constexpr size_t kV8MaxWasmTableEntries = 10000000;
 constexpr size_t kV8MaxWasmTables = 1;
 constexpr size_t kV8MaxWasmMemories = 1;
 
 constexpr size_t kSpecMaxWasmMemoryPages = 65536;
 constexpr size_t kSpecMaxWasmTableSize = 0xFFFFFFFFu;
 
 constexpr uint64_t kWasmMaxHeapOffset =
     static_cast<uint64_t>(
         std::numeric_limits<uint32_t>::max())  // maximum base value
     + std::numeric_limits<uint32_t>::max();    // maximum index value
 
 // Limit the control stack size of the C++ wasm interpreter.
 constexpr size_t kV8MaxWasmInterpretedStackSize = 64 * 1024;
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_WASM_LIMITS_H_