libc : implement signal()

[adityachopra29]

Creates implementation stub for signal() using sigaction.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[adityachopra29]

Note : I have attempted to create a wrapper around the sigaction() function for signal, but since all these function only have stubs, I was not sure how to test them. Moreover, since there already exists a test to check existence of the function at tests/posix/headers/src/signal_h.c, and I did not find tests for anything else regarding the same, I have not added any tests.

Do let me know if any tests need to be added.

[cfriedt]

@adityachopra29 - if it's just a stub, then it would probably make sense to simply return SIG_ERR and set errno to ENOSYS.

Also, given that signal() is a c89 function, it would probably make sense to move this under the common libc rather than under POSIX.