function exactEquals(a, b) {
  return a[0] === b[0] && a[1] === b[1] && a[2] === b[2] && a[3] === b[3] && a[4] === b[4] && a[5] === b[5] && a[6] === b[6] && a[7] === b[7] && a[8] === b[8];
}
Returns whether or not the matrices have exactly the same elements in the same position (when compared with ===)

@param {mat3} a The first matrix.
@param {mat3} b The second matrix.
@returns {Boolean} True if the matrices are equal, false otherwise.