On 64-bit platforms more collisions can be prevented by spreading
the three 32-bit values more widely apart.

Bug: b/137649247
Change-Id: Icf429b4fc5a3d5d4472b346b190e48ac429bf881
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/34929
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>