@Override
		public void visitVal(JitVal v) {
			if (!add(v)) {
				return;
			}
			JitOpUpwardVisitor.super.visitVal(v);
		}
An upward graph traversal for collecting all values in the use-def graph.

@see #allValues()
@see #allValuesSorted()
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emu/jit/analysis/JitDataFlowModel.java