public HighSymbol getParam(int i) {
		if (localsyms != null) {
			return localsyms.getParamSymbol(i);
		}
		return null;
	}
@param i i'th parameter index
@return the i'th HighParam to this function prototype or null
if this prototype is not backed by a LocalSymbolMap
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/pcode/FunctionPrototype.java