private void coalesceVarnodes() {
		Set<Varnode> allVarnodes = new HashSet<>();
		for (JitBlock block : cfm.getBlocks()) {
			allVarnodes.addAll(dfm.getAnalyzer(block).getVarnodesRead());
			allVarnodes.addAll(dfm.getAnalyzer(block).getVarnodesWritten());
		}
		for (Varnode varnode : allVarnodes) {
			if (!varnode.isAddress()) {
				coalesceVarnode(varnode);
			}
		}
	}
Check for overlap when one varnode is known to be to the left of the other.

@param left the left varnode (having lower address)
@param right the right varnode (having higher address)
@return true if they overlap (not counting abutting), false otherwise.
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emu/jit/analysis/JitVarScopeModel.java