Fix for use of UNPREDICTABLE register combination

Use of the LDRD instruction form LDRD Rt, Rt2, [Rn, Rm] has restrictions
on the register combinations - specifically if Rt or Rt2 is equal to Rn or
Rm the behaviour is defined as 'UNPREDICTABLE'.

Change-Id: I19834783865e07897cc7012367e698447f023ce6
5 files changed