Ideas about visualizing callers / callees in the same graph with a sandwich or butterfly view

• JMC-6872, that hints about a butterfly view to display predecessors / successors.

  See https://github.com/jlfwong/speedscope#-sandwich

  

  The Sandwich view is a table view in which you can find a list of all functions and their associated times. You can sort by self time or total time. It's called "Sandwich" view because if you select one of the rows in the table, you can see flamegraphs for all the callers and callees of the selected row.

• Go’s pprof tool recently gained a view for viewing simultaneously method callers and callees.

  Basically it has the look of the flame graph, but works kind of like the call graph view.

  

  More informations are in the commit message.