executors/OBJC: fix executor

[int-y1]

• This executor calls prctl with 23.
• This executor tries to traverse ~/GNUstep, but this directory doesn't exist. I did RecursiveDir('~') to work around this issue.
• Apparently, initialize(cls) doesn't run. I wrote autoconfig(cls) to do the setup.
• Afterwards, add apt-get install make gnustep-devel to the DMOJ dockerfile.

[dmoj-build]

Can one of the admins verify this patch?

[codecov-commenter]

Codecov Report

Attention: 15 lines in your changes are missing coverage. Please review.

Comparison is base (e51da7a) 82.99% compared to head (8aac5cd) 82.91%.
Report is 1 commits behind head on master.

Files	Patch %	Lines
dmoj/executors/OBJC.py	48.00%	13 Missing ⚠️
dmoj/cptbox/isolate.py	0.00%	2 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1158      +/-   ##
==========================================
- Coverage   82.99%   82.91%   -0.08%     
==========================================
  Files         141      141              
  Lines        5362     5373      +11     
==========================================
+ Hits         4450     4455       +5     
- Misses        912      918       +6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[quantum5]

ok to test

[Xyene]

This executor tries to traverse ~/GNUstep, but this directory doesn't exist. I did RecursiveDir('~') to work around this issue.

In what way does it fail if you don't allow ~, and allow ~/GNUstep instead?

[int-y1]

This executor tries to traverse ~/GNUstep, but this directory doesn't exist. I did RecursiveDir('~') to work around this issue.

In what way does it fail if you don't allow ~, and allow ~/GNUstep instead?

0.414 Testing OBJC:   Failed self-test                                                                                                                                                                
0.500   Attempted:                                                                                                                                                                                    
0.502     gcc: /usr/bin/gcc
...
0.502   Errors:
0.502     Traceback (most recent call last):
0.502       File "/judge/dmoj/executors/base_executor.py", line 337, in run_self_test
0.502         executor = cls(cls.test_name, utf8bytes(cls.test_program))
0.502                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
0.502       File "/judge/dmoj/executors/compiled_executor.py", line 63, in __call__
0.502         obj.compile()
0.502       File "/judge/dmoj/executors/compiled_executor.py", line 212, in compile
0.502         self.warning = self.get_compile_output(process)
0.502                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
0.502       File "/judge/dmoj/executors/compiled_executor.py", line 194, in get_compile_output
0.502         self.handle_compile_error(output)
0.502       File "/judge/dmoj/executors/compiled_executor.py", line 205, in handle_compile_error
0.502         raise CompileError(output)
0.502     dmoj.error.CompileError: cc1obj: error: /home/judge/GNUstep/Library/Headers: Permission denied

[Xyene]

LGTM, thanks!