public PcodeOpAST getPreviousPcodeOpAST() {
		return previousPcodeOp;
	}
Returns the previous PcodeOpAST correspond to the features.  Only non-null for DUAL_FLOW 
features.
@return previous pcodeop ast
Ghidra/Features/BSimFeatureVisualizer/src/main/java/ghidra/bsfv/BsfvRowObject.java