[tests] Use Dune Cram tests for fc_script directory

tests/fc_script/build-callgraph.t/build-callgraph.c

tests/fc_script/build-callgraph.t/run.t

tests/fc_script/dune

tests/fc_script/estimate-difficulty.t/estimate-difficulty.c

tests/fc_script/estimate-difficulty.t/run.t

tests/fc_script/find-fun.t/build-callgraph.c

tests/fc_script/find-fun.t/find-fun.c

tests/fc_script/find-fun.t/find-fun2.c

tests/fc_script/find-fun.t/list-functions.c

tests/fc_script/find-fun.t/main.c

tests/fc_script/find-fun.t/main2.c

tests/fc_script/find-fun.t/main3.c

tests/fc_script/find-fun.t/make-wrapper.c

tests/fc_script/find-fun.t/make-wrapper2.c

tests/fc_script/find-fun.t/make-wrapper3.c

tests/fc_script/find-fun.t/run.t

tests/fc_script/flamegraph.t/flamegraph.txt

tests/fc_script/flamegraph.t/run.t

tests/fc_script/for-list-functions.h

...heuristic-detect-recursion.t/heuristic-detect-recursion.i