Fix coccinelle linking regression test on Cygwin

[dra27]

#13673 added a test which includes:

ocaml/testsuite/tests/badly-ordered-deps/cocinelle.ml

Lines 27 to 29 in 49baed7

	output="cocinelle";
	all_modules = "a.cmx cocinelle.cmx";
	program="./cocinelle.exe";

where the program is cocinelle.exe (on all platforms) and result of running that program is sent to the file concinelle.

This doesn't work on Cygwin, as cocinelle.exe is created first, and at that point cocinelle and cocinelle.exe are the same file. When ocamltest tries to run ./cocinelle.exe it dutifully redirects stdout to cocinelle and Cygwin dutifully truncates concinelle.exe. Executing an empty executable returns code 0, and then the check on the output correctly fails.

I've fixed it by adding .output (which is what the only other test which uses this feature does), although it's not entirely clear to me why either output or program is being set here, @Octachron?

[Octachron]

I really don't remember a good reason for setting either program or output beyond the point that the test did fail before the corresponding bug fix.

[gasche]

Note: I believe that the correct spelling is "coccinelle" (see the software page), with two consecutive "c" to sound like an "x", so while we are at it we could also fix this.

[dra27]

• s/cocinelle/coccinelle
• program and output both removed from the ocamlopt test (test still works on both Linux and Cygwin and hopefully CI will agree)
• reverted #13669: use compilation unit name in dependency check for the native linker #13673 and checked that the test then fails