@Override
	public SleighSymbol findSymbol(String nm) {
		SleighSymbol sym = symbolMap.get(nm);
		if (sym != null) {
			return sym;
		}
		return sleigh.findSymbol(nm);
	}
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