X86: Properly handle bad FPU opcode

X86: Properly handle bad FPU opcode

Since Bad_Opcode and FGRPd9_2 were the same in i386-dis.c, all
Bad_Opcode entries in float_reg were displaced as FGRPd9_2.  This
patch adds an entry for Bad_Opcode in fgrps to avoid treating it
as FGRPd9_2.

gas/

	PR binutils/20775
	* testsuite/gas/i386/i386.exp: Run fpu-bad.
	* testsuite/gas/i386/fpu-bad.d: New file.
	* testsuite/gas/i386/fpu-bad.s: Likewise.

opcodes/

	PR binutils/20775
	* i386-dis.c (FGRPd9_2): Replace 0 with 1.
	(FGRPd9_4): Replace 1 with 2.
	(FGRPd9_5): Replace 2 with 3.
	(FGRPd9_6): Replace 3 with 4.
	(FGRPd9_7): Replace 4 with 5.
	(FGRPda_5): Replace 5 with 6.
	(FGRPdb_4): Replace 6 with 7.
	(FGRPde_3): Replace 7 with 8.
	(FGRPdf_4): Replace 8 with 9.
	(fgrps): Add an entry for Bad_Opcode.