PPC: Mnemonic incorrectly assigned to unconditional BCL instruction

[EdwardLarson]

When the BO value is 1x1xx (xs being ignored), the branch is always taken (despite the fact that this is supposedly a "conditional branch"). However when disassembling machine code for this instruction, the assembly bdnz is emitted.

For example:

cstool ppc64be "\x42\x9f\x00\x05" 0x0
 0  42 9f 00 05  bdnzl	0x4

Expected:

cstool ppc64be "\x42\x9f\x00\x05" 0x0
> 0  42 9f 00 05  bcl	0x14, 31, 0x4

(bdnz is a mnemonic for BO=1x00x - decrement CTR and branch if result not equal to 0)

[EdwardLarson]

This may be related to issue #970 however this is not just detail information being lost, this instruction is being incorrectly assigned a mnemonic which means something else.