PPC64 ISA 3.0B, add support for the additional instructions: addex, mffscdrn,

PPC64 ISA 3.0B, add support for the additional instructions: addex, mffscdrn,
mffscdrni, mffsce, mffscrn, mffscrni, mffsl. vmsumudm.

Additionally, the OV32 and CA32 bits were introduced in ISA 3.0 but
Valgrind add support for setting these bits for ISA 3.0.  The OV32 and CA32
bits must now be set on a number of pre ISA 3.0 instructions.  So now the
instructions produce different results in the XER register.  Thus we need pre
and post ISA 3.0 expect files.  Command line options were added to thee
pre ISA test cases so instructions that didn't change could be run with one
set of command line args.  The instructions that have different XER results
are run using a different set of command line args.  The tests were split into
two, one for instructions that didn't change on for instructions that do
change under ISA 3.0.  We then create ISA3.0 expect files only for the tests
that run differently.  By doing this we minimized the size of the expect files
needed.

Valgrind bugzilla 378931

git-svn-id: svn://svn.valgrind.org/vex/trunk@3359