[wasm] test deserialization when header is invalid

src/snapshot/serializer-common.h

Index: src/snapshot/serializer-common.h
diff --git a/src/snapshot/serializer-common.h b/src/snapshot/serializer-common.h
index 74b02180739e4138f086546d04f8df7515bff114..1ca0a5f732a332ddc07c1f5695b7c17dc82f0a44 100644
--- a/src/snapshot/serializer-common.h
+++ b/src/snapshot/serializer-common.h
@@ -253,11 +253,15 @@ class SerializedData {
   }
 
  protected:
-  void SetHeaderValue(int offset, uint32_t value) {
-    uint32_t* address = reinterpret_cast<uint32_t*>(data_ + offset);
+  static void SetHeaderValueInBuffer(byte* buffer, int offset, uint32_t value) {
+    uint32_t* address = reinterpret_cast<uint32_t*>(buffer + offset);
     memcpy(reinterpret_cast<uint32_t*>(address), &value, sizeof(value));
   }
 
+  void SetHeaderValue(int offset, uint32_t value) {
+    SetHeaderValueInBuffer(data_, offset, value);
+  }
+
   uint32_t GetHeaderValue(int offset) const {
     uint32_t value;
     memcpy(&value, reinterpret_cast<int*>(data_ + offset), sizeof(value));