* Store static variable values in eval array (two dimensions: TU and variable
    name)
  * Save static variable values in ctxsw
  * Implement associative arrays
    - TBD: syntax/functions
    - Use `__x__` between array name and index name
      Example: array `arr_` and index `ind`: stored as `__arr_arr___x__ind`
      Example: array `arr` and index `_ind`: stored as `__arr_arr__x___ind`
      Example: array `arr_` and index `_ind`: stored as `__arr_arr___x___ind`