Fix the partial disassembly of a broken three byte instruction at the end of a function.

Fix the partial disassembly of a broken three byte instruction at the end of a function.

opcodes	* i386-dis.c (print_insn): Fix decoding of three byte operands.

tests	* gas/i386/intel.s: Add test of disassembly of a potential
	three byte instuction at the end of a function.
	* gas/i386/intel.d: Update expected disassembly.