Merge "Do not create a map with start == end." am: 6a065202

  for (uint8_t i = 0; i < entry_count; i++) {

    uint64_t start = AlignToPage(data_provider->ConsumeIntegral<uint64_t>());

    uint64_t end = AlignToPage(data_provider->ConsumeIntegralInRange<uint64_t>(start, UINT64_MAX));

    if (start == end) {

      // It's impossible to see start == end in the real world, so

      // make sure the map contains at least one page of data.

      if (__builtin_add_overflow(end, 0x1000, &end)) {

        continue;

      }

    }

    // Make sure not to add overlapping maps, that is not something that can

    // happen in the real world.

    auto entry = map_ends.upper_bound(start);