public JitDirectMemoryVar generateDirectMemoryVar(Varnode vn) {
		return new JitDirectMemoryVar(nextVarId(), vn);
	}
Generate a variable representing a direct memory access

@param vn the varnode, which ought to be neither register nor unique
@return the variable
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emu/jit/analysis/JitDataFlowModel.java