protected AssemblyNonTerminal createWildNonTerminal(AssemblySymbol s) {
		WildAssemblyTerminal wt = generateWildTerminal(s);
		if (wt == null) {
			return null;
		}
		WildAssemblyNonTerminal nt =
			new WildAssemblyNonTerminal("w`" + s.getName(), s.takesOperandIndex());
		grammar.addProduction(new WildAssemblyProduction(nt, new AssemblySentential<>(s)));
		grammar.addProduction(new WildAssemblyProduction(nt, new AssemblySentential<>(wt)));
		return nt;
	}
Exclude string terminals. These should be purely syntactic elements. Use of them as fixed
literals, e.g., 1 or RAX, is an error on the spec's part.
Ghidra/Features/WildcardAssembler/src/main/java/ghidra/asm/wild/WildSleighAssemblerBuilder.java