These opcodes cannot be disassembled because op_sel operand is missing - it must be added manually.
See bug 56512 for detailed issue analysis.
A similar problem is being addressed in https://reviews.llvm.org/D129084, but it affects different opcodes.
This is a very similar to the code in convertVOP3PDPP. Can we de-duplicate it and create a helper function that collects all modifier values?