DLSHIFT DRSHIFT bug

[Ed8562]

DLSHIFT DRSHIFT give wrong results for these corner cases:

03 01 bits/cell dlshift \ expected: 00 03 gives: 03 03 FF 00 bits/cell dlshift \ expected: 00 FF gives: FF FF 00 01 bits/cell drshift \ expected: 01 00 gives: 01 01 00 FF bits/cell drshift \ expected: FF 00 gives: FF FF

Works using 8086 cpu but not the later cpu's which mask the shift count.

There's also an issue when shift count is zero.