Convert the output from many profilers into a Graphviz dot graph

Current versions

gprof2dot requires the following formula to be installed:
graphviz 2.40.1 Graph visualization software from AT&T and Bell Labs

Formula history

ilovezfs Audit fixes for descriptions (#20013)
ilovezfs gprof2dot: fix heredoc in test (#19683)
ilovezfs Use “squiggly” heredocs.
ilovezfs gprof2dot: use assert_predicate instead of File.exist?
ilovezfs gprof2dot 2017.9.19
Izaak Beekman gprof2dot 2016.10.13
Mike McQuaid Use hash rockets again. (#5177)
Mike McQuaid Use Ruby 1.9+ symbol hash keys in all formulae. (#4942)
Izaak Beekman gprof2dot 2015.02.03 (new formula)