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

src/wasm/wasm-external-refs.cc

Index: src/wasm/wasm-external-refs.cc
diff --git a/src/wasm/wasm-external-refs.cc b/src/wasm/wasm-external-refs.cc
index e155f3c8ba64fb0f0c321e8f307bcf384533426b..6ae15976736333c8cebb8be76d3225960c9fdd74 100644
--- a/src/wasm/wasm-external-refs.cc
+++ b/src/wasm/wasm-external-refs.cc
@@ -194,6 +194,26 @@ 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