[mlir][CallGraph] Missed visibility for CallGraphNode to construct AbstractEdge

[Luhaocong]

Hi River @River707 @tensorflower-gardener ，In CallGraph Analysis, I find a AbstractEdge will always be added to target CallGraphNode from externalCallerNode, no matter the target is a public or private FunctionOpInterface (which is derived class of CallableOpInterface) .

llvm-project/mlir/lib/Analysis/CallGraph.cpp

Lines 125 to 131 in c17a914

	// Otherwise, connect all callable nodes to the external node, this allows
	// for conservatively including all callable nodes within the graph.
	// FIXME This isn't correct, this is only necessary for callable nodes
	// that *could* be called from external sources. This requires extending
	// the interface for callables to check if they may be referenced
	// externally.
	externalCallerNode.addAbstractEdge(node.get());

Is there any plan to add visibility for CallableOpInterface to get better analysis result ？Or could you please give me some advice, I can try to fix this problem?

[Luhaocong]

move to #116177

[EugeneZelenko]

Not merged yet.