Change VAO hash value function

Change VAO hash value function

Since std::hash<uint32_t>{}(i); just return itself,
we need to make some other method to calculate hash of location.

For example, 0 location doesn't have any mean.
and location with 1, 3 will collision as location 2.

To avoid this hash collision, let we change some hash generate method.

  v = i + 1;
  hash += v << 24;
  v *= v;
  v ^= i;
  hash += v << 16;
  v *= v;
  hash += v;

Note that if we skip v ^= i; operation, collision occured when location is
near 13.

Change-Id: Ie081d9a5e8895988ca7183dfc860176b69c4e337
Signed-off-by: Eunki Hong <eunkiki.hong@samsung.com>