message: [SwiftLanguageRuntime] Simplify Error dynamic type lookup.
  We don't really need the witness table pointer, so don't bother
  computing it.
diff: @@ -1587,12 +1587,6 @@ bool SwiftLanguageRuntime::IsValidErrorValue(
  return false;
  lldb::addr_t witness_table_location = metadata_location + ptr_size;
  - lldb::addr_t witness_table_ptr_value =
  - m_process->ReadPointerFromMemory(witness_table_location, error);
  - if (witness_table_ptr_value == 0 ||
  - witness_table_ptr_value == LLDB_INVALID_ADDRESS || error.Fail())
  - return false;
  -
  lldb::addr_t payload_location = witness_table_location + ptr_size;
  if (out_error_descriptor) {
  