Power PC, add the two privileged Transactional Memory instructions.

The initial Transactional Memory instruction patch did not include the two
privileged (OS) instructions treclaim and trechkpt. VEX commit 2784 added
the support for these two instructions.

This patch adds a touch test to make sure all of the POWER Transactional
memory instrutions are recognized by Valgrind.  All of the the Transactional
Memory instructions, with the exception of tbegin, are treated as NOPs in the
first implementation.  The tbegin instruction causes the transaction to fail
thus no additional Transactional Memory instructions on the successful
transaction path would be executed in a real program.  This test just makes
sure each instruction is actually recognized by Valgrind.

The patch if for Bugzilla 325751.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13630 a5019735-40e9-0310-863c-91ae7b9d1cf9