In various places we have code that does the equivalent of

do_something(uint x) {
  uint next_pow2 = 1;
  while (next_pow2 < x)  {
    next_pow2 <<= 1;
  }
  ...
}

This is brittle (would loop forever if x > (1 << 31)) and also somewhat inefficient. Adding a utility that does the equivalent of 

if (x == 0) {
  next_pow2 = 1;
} else if (x < (1 << 31)) {
  next_pow2 = 1U << (32 - count_leading_zeros(x));
} else {
  next_pow2 = uint_max; // might need to be able to allow different behaviors here 

might avoid infinite loops at the extreme (although it's debatable what should be returned when x > 2^31) and potentially be more efficient.