Rename some instructions for consistency and sanity: use "_UPD" suffix for

Rename some instructions for consistency and sanity: use "_UPD" suffix for
load/stores with address register writeback, and use "odd" suffix to distinguish
instructions to access odd numbered registers (instead of "a" and "b").
No functional changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99066 91177308-0d34-0410-b5e6-96231b3b80d8