Test more modules from the Stdlib

[jmid]

We should extend the test suite to include more modules from the Stdlib. There's an overview here: https://github.com/ocaml/ocaml/issues/10960#issue-1117254143 We may want to prioritize tests of modules with a Y in one of the first two columns, over tests of purely functional code modules.

[OlivierNicole]

Currently tested modules (to update as needed):

Module	Lin test	STM test	Other test	Notes
arg.ml
array.ml	X	X		Not domain-safe
atomic.ml	X	X
bigarray.ml	X	X		Not domain-safe
buffer.ml		X		Not domain-safe
bytes.ml	X	X		Not domain-safe
camlinternalFormat.ml
camlinternalLazy.ml	X	X		Not domain-safe
camlinternalMod.ml
domain.ml			X
ephemeron.ml		X		Not domain-safe
filename.ml
float.ml	X	X		(tests of Float.Array)
format.ml
gc.ml
hashtbl.ml	X	X		Not domain-safe
in_channel.ml	X			Not domain-safe
lexing.ml
obj.ml
oo.ml
out_channel.ml		X		Not domain-safe
parsing.ml
printexc.ml
printf.ml
queue.ml	X			Not domain-safe
random.ml
scanf.ml				Documented as domain-unsafe
semaphore.ml		X
stack.ml	X			Not domain-safe
stdlib.ml
sys.ml		X		Not domain-safe
weak.ml		X		Not domain-safe

otherlibs

Module	Lin test	STM test	Other test	Notes
unix/unix.ml
str/str.ml				Should have been made domain-safe by #10670
systhreads/thread.ml			X
dynlink/	X			Not domain-safe

[jmid]

Thanks for this overview! :pray: