or1k-32: Add or1k package with instruction decode logic generated by gendec.
cmd/gendec: Fix generated padding check logic.
cmd/gendec: Update list.txt.
orbis: Add l.ld instruction. Fix Src2 type of Lhs struct. Add Buf field to custN.
or1k-32: Implement instruction decoding and fix padding check.
cmd/gendec: Fix parsing of operands.
cmd/gendec: Use lower case for generated operand names.
cmd/gendec: Update bits of l.ff1 and l.fl1 in list.txt.
orbis: Implement String method for l.custN.