Modify POWER9 support to match final ISA 3.0 documentation.

Modify POWER9 support to match final ISA 3.0 documentation.

opcodes/
	* ppc-opc.c (powerpc_opcodes) <slbiag>: New mnemonic.
	<addex., brd, brh, brw, lwzmx, nandxor, rldixor, setbool,
	xor3>: Delete mnemonics.
	<cp_abort>: Rename mnemonic from ...
	<cpabort>: ...to this.
	<setb>: Change to a X form instruction.
	<sync>: Change to 1 operand form.
	<copy>: Delete mnemonic.
	<copy_first>: Rename mnemonic from ...
	<copy>: ...to this.
	<paste, paste.>: Delete mnemonics.
	<paste_last>: Rename mnemonic from ...
	<paste.>: ...to this.

gas/
	* testsuite/gas/ppc/power9.d <slbiag, cpabort> New tests.
	<addex., brd, brh, brw, lwzmx, nandxor, rldixor, setbool,
	xor3, cp_abort, copy_first, paste, paste_last, sync>: Remove tests.
	<copy, paste.>: Update tests.
	* testsuite/gas/ppc/power9.s: Likewise.