Added 'r' or 'i' annotations to instructions, as SparcInstr.def has changed.

Non-obvious change: since I have changed ST and STD to be STF and STDF to
(a) closer resemble their name (NOT assembly text) in the Sparc manual, and
(b) clearly specify that they they are floating-point opcodes,
I made the same changes in this file.

llvm-svn: 6376