The current code is not properly handling a non-zero TH field in the
dcbt instruction, which is valid for several forms of data cache block
touch instructions.  This patch adds the needed support to
VEX/priv/guest_ppc_toIR.c.

Bugzilla 324518

git-svn-id: svn://svn.valgrind.org/vex/trunk@2751 8f6e269a-dfd6-0310-a8e1-e2731360e62c