Sync in latest vDSOs from upstream.

• Use conditional instruction to simplify the ARMv6 vDSO. This means that we no longer perform any branching. In the failure case, we simply slide over the assignments of the return values.
  
  The vDSO could be improved even further by using stmia to do assignments in parallel. Unfortunately, the script used to generate these is not smart enough for that (yet).
  
  Spotted by: andrew@.

• Make the style of the i686 vDSO more similar to the others by using decimal literals.