Fix wrong endianness of wasm header in WasmModuleWriter on big-endian platforms

src/wasm/wasm-external-refs.cc

 // 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.
 
 #include <math.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <limits>
 
 #include "include/v8config.h"
@@ skipping 176 matching lines @@
 }
 
 uint32_t word32_popcnt_wrapper(uint32_t* input) {
   return static_cast<uint32_t>(base::bits::CountPopulation(*input));
 }
 
 uint32_t word64_popcnt_wrapper(uint64_t* input) {
   return static_cast<uint32_t>(base::bits::CountPopulation(*input));
 }
 
+uint32_t word32_to_little_endianness(const uint32_t* input) {
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+  return *input;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+  return base::bits::ChangeEndianness(*input);
+#else
+#error Unknown endianness
+#endif
+}
+
+uint32_t word32_to_natural_endianness(const uint32_t* input) {
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+  return *input;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+  return base::bits::ChangeEndianness(*input);
+#else
+#error Unknown endianness
+#endif
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8