public boolean isUsed(JitOp op) {
		if (context.getConfiguration().removeUnusedOperations()) {
			return used.contains(op);
		}
		return true;
	}
Check whether the given op node is used.

<p>
If the op is used, then it cannot be eliminated.

@param op the op to check
@return true if used, i.e., non-removable
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emu/jit/analysis/JitOpUseModel.java