Trying to figure out whether the other 2 asserts could trigger, the idea
to just delay everything that could potentially re-sort the array and
thereby invalidate the current iteration index seemed appealing.

Should be faster too: the main loop now looks at each hint only once,
but deleting a hint now requires a O(log(n)) GetStartOf() lookup.

Change-Id: I5c7b8493b35ee71c8ebdc284d2508c9812dc29cf