@Override
	protected void onMissingUseropDef(PcodeOp op, PcodeFrame frame, String opName,
			PcodeUseropLibrary<Object> library) {
		branchesForThisStep.add(
			new ErrBranch(op, "Sleigh userop '%s' is not in the library".formatted(opName)));
	}
{@inheritDoc}

<p>
This create an {@link ErrBranch} record and collects it for this instruction step. The record
will first be used to check for fall through. Then, the passage decoder is notified, which
collects the records to later passage-wide control flow analysis. In contrast to
{@link #badOp(PcodeOp)}, an instruction that calls a missing userop may still have fall
through.
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emu/jit/decode/DecoderExecutor.java