This patch contains the fowllowing hacks:
(1) Add "--timetable-data=FILE" option for test-all
This option enables to dump timeline event
contains worker, suite, and start/end time.
(2) remove TestJIT in test_jit_debug.rb on parallel test.
it is duplicated test.
(3) move test_jit.rb and test_jit_debug.rb at first
because these two tests are bottleneck of parallel tests.
On my environment, `make test-all TESTS=-j12` reduced the total time
190 seconds -> 140 seconds.
Fix https://github.com/ruby/ruby/runs/636020145 without skipping too
many tests.
It seems that .c -> .o with debug flags and .o -> .so without debug
flags did not generate .dSYM but now .c -> .so with debug flags seems to
generate a .dSYM directory. As --jit-debug should not be used by normal
users, let me skip implementing the removal for now.
