arch-power: Refactor shift instructions

This changes the format for integer shift instructions
such that the computation of the carry bit is implicitly
handled rather than including it in the definition of an
instruction.

Change-Id: Ib916597287efd51b2c9e8781209a8019f2fc38e8
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40924
Reviewed-by: Boris Shingarov <shingarov@labware.com>
Maintainer: Boris Shingarov <shingarov@labware.com>
Tested-by: kokoro <noreply+kokoro@google.com>
3 files changed