Remove the Long2 type.

Remove the Long2 type.

Bug swiftshader:6

Change-Id: Idb083bd1aecedb529f4e15deda3a1cfcf95a5bfa
Reviewed-on: https://swiftshader-review.googlesource.com/7753
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-on: https://swiftshader-review.googlesource.com/8133
Reviewed-by: Alexis Hétu <sugoi@google.com>