Support invoke tree #2
Description
For example-2 which outputs the following invoke summary
summary of tracer_ctx_t::global (4.386451s)
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count cumulative (s) % mean (ms) call site
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1 4.386159 99.99 4386.1591 main
43 4.385608 99.98 101.9909 work
1 4.374317 99.72 4374.3174 h
1 0.010054 0.23 10.0539 g
1 0.001700 0.04 1.6999 f
it should output the invoke tree in addition
invoke tree of tracer_ctx_t::global (4.386451s)
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count cumulative (s) % mean (ms) call chain
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43 main
1 |-f
20 | |-work
1 |-g
10 | |-work
1 |-h
13 |-work