i965: Fill out instruction list.

i965: Fill out instruction list.

Add some instructions: illegal, movi, sends, sendsc.

Remove some instructions with reused opcodes: msave, mrestore, push,
pop, goto. I did have some gross code for disassembling opcodes
per-generation, but there's very little meaningful overlap so it's
probably not needed.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>