X86: Reuse opcode 0x80 decoder for opcode 0x82

Since opcode 0x82 is an alias of opcode 0x80, we can reuse opcode 0x80
decoder.

	* i386-dis.c (REG_82): Removed.
	(X86_64_82_REG_0): Likewise.
	(X86_64_82_REG_1): Likewise.
	(X86_64_82_REG_2): Likewise.
	(X86_64_82_REG_3): Likewise.
	(X86_64_82_REG_4): Likewise.
	(X86_64_82_REG_5): Likewise.
	(X86_64_82_REG_6): Likewise.
	(X86_64_82_REG_7): Likewise.
	(X86_64_82): New.
	(dis386): Use X86_64_82 instead of REG_82.
	(reg_table): Remove REG_82.
	(x86_64_table): Add X86_64_82.  Remove X86_64_82_REG_0,
	X86_64_82_REG_1, X86_64_82_REG_2, X86_64_82_REG_3,
	X86_64_82_REG_4, X86_64_82_REG_5, X86_64_82_REG_6 and
	X86_64_82_REG_7.