mfvrd and mffprd are both alias to mfvrsd. This patch enables correct parsing of the aliases, but we still emit a mfvrsd. Committing on behalf of brunoalr (Bruno Rosa). Differential Revision: https://reviews.llvm.org/D29177 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297849 91177308-0d34-0410-b5e6-96231b3b80d8