Increase the number of vector registers available for allocation from
3 to 5.


git-svn-id: svn://svn.valgrind.org/vex@2881 8f6e269a-dfd6-0310-a8e1-e2731360e62c
Fix an enum type confusion, PPCAvFpOp vs PPCAvOp, as excellently
detected by Clang.  Gcc, are you paying attention?


git-svn-id: svn://svn.valgrind.org/vex@2882 8f6e269a-dfd6-0310-a8e1-e2731360e62c