(m68k_opcodes): New type characters "3" for 68030 MMU regs and "t" for
immediate 0-7 added. Set up some opcodes (ptest, bkpt) to use them.
Tightened description of "fmovex" to distinguish it from some "pmove"
encodings. Added "pmove" for 68030 MMU regs, cleaned up descriptions that
claimed versions were available for chips not supporting them. Added
"pmovefd".
sparc.h: Fixed up some comments.