Allow early-writeback for the cases
   stp d, d, [sp,#-imm]!
   stp s, s, [sp,#-imm]!
as well as for the existing case
   stp q, q, [sp,#-imm]!



git-svn-id: svn://svn.valgrind.org/vex/trunk@2854 8f6e269a-dfd6-0310-a8e1-e2731360e62c
Handle IRStmt::STle of type F32.


git-svn-id: svn://svn.valgrind.org/vex/trunk@2855 8f6e269a-dfd6-0310-a8e1-e2731360e62c
Enable 'smulh'.


git-svn-id: svn://svn.valgrind.org/vex/trunk@2856 8f6e269a-dfd6-0310-a8e1-e2731360e62c