public void addOperand(Location loc, String name, int index) {
		OperandSymbol sym = new OperandSymbol(loc, name, index, null);
		addSymbol(sym);
	}
Inject a symbol representing an "operand" to the pcode snippet.

<p>
This puts a placeholder in the resulting template, which gets filled in with the context
specific storage locations when final p-code is generated

@param loc is location information for the operand
@param name of operand symbol
@param index to use for the placeholder
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/lang/PcodeParser.java