/* there needs to be support for Unicode here,
unless we pretend that we can redefine the MD-5
algorithm for multi-byte characters (perhaps
by adding every four 16-bit characters and
shortening the sum to 32 bits). Otherwise
I suggest performing MD-5 as if every character
was two bytes--e.g., 0040 0025 = @%--but then
how will an ordinary MD-5 sum be matched?
There is no way to standardize text to something
like UTF-8 before transformation; speed cost is
utterly prohibitive. The JavaScript standard
itself needs to look at this: it should start
providing access to strings as preformed UTF-8
8-bit unsigned value arrays.
function(s) {
    /* I figured global was faster.   */
    let md5blks = [],
      i; /* Andy King said do it this way. */
    for (i = 0; i < 64; i += 4) {
      md5blks[i >> 2] =
        s.charCodeAt(i) +
        (s.charCodeAt(i + 1) << 8) +
        (s.charCodeAt(i + 2) << 16) +
        (s.charCodeAt(i + 3) << 24);
    }
    return md5blks;
  }