Previously these hashes were 0 and -1 respectively. These seem like common
sentinel values and should be avoided to prevent needless collisions.
This patch changes those values to different arbitrary numbers, which should
hopefully cause less collisions. Because I couldn't help myself I choose the
fundamental constants for gravity and the speed of light.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@288623 91177308-0d34-0410-b5e6-96231b3b80d8
