The only reasonable way I could find to do this is to provide an alternate
version of the addrmode6 operand with a different encoding function. Use it
for all the VLD-dup instructions for the sake of consistency.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120358 91177308-0d34-0410-b5e6-96231b3b80d8
