public JitPhiOp generatePhi(JitDataFlowModel dfm, JitBlock block) {
		return dfm.notifyOp(new JitPhiOp(block, dfm.generateOutVar(varnode)));
	}
Create the {@link JitPhiOp phi} node for this missing variable.

The resulting node and its {@link JitPhiOp#out() output} are added to the use-def graph. Note
that this missing variable never enters the use-def graph. The phi's output takes the place
of this variable.

@param dfm the data flow model
@param block the block containing the op that accessed the varnode
@return the generated phi op
@see JitDataFlowModel Inter-block data flow analysis
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emu/jit/var/JitMissingVar.java