Valgrind regression test fix for stfdpx instruction.

Valgrind regression test fix for stfdpx instruction.

There is a bug in the stfdpx instruction test for ppc32 and ppc64.
The inline assembly to move the arguments into the registers before
the store instruction were moving from the register not to the
register.  The error has been fixed.  This results in a change in
the expected output.

Additionally, it was noted that the inline assembly was using "f" rather
then "d" for the double arguments.  Similarly, the prints should have
been %lf not %f for doubles.  These changes were made but they did not
change the output of the tests.

This patch fixes Vagrind bugzilla 339020.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14545