https://github.com/openjdk/jdk/blob/9f0e7da64e21237322e55ca4f0e3639fa5d1c4ed/src/hotspot/share/classfile/stringTable.cpp#L322-L330

oop StringTable::intern(Symbol* symbol, TRAPS) {
  if (symbol == nullptr) return nullptr;
  ResourceMark rm(THREAD);
  int length;
  jchar* chars = symbol->as_unicode(length);
  Handle string;
  oop result = intern(string, chars, length, CHECK_NULL);
  return result;
}

"chars" is copied just to compute the hashcode. We should try to compute the hashcode using the UTF8 characters in the Symbol.

This is called quite often when loading classes from classfiles (but not when CDS is used):

java -Xshare:off -cp . HelloWorld
- called 1600 times

java -Xshare:on -cp . HelloWorld
- called 17 times

Important: we need to be 100% sure that we get the hashcode computation correct!