[llvm] [Support][test] Fix OpenDirectoryAsFileForRead test on AIX and z/OS (PR #216241)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `libc-x86_64-debian-dbg-bootstrap-build` running on `libc-x86_64-debian` while building `llvm` at step 4 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/200/builds/35340

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 4 (annotate) failure: 'python ../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py ...' (failure)
...
-- Skipping test for 'libc.src.string.memset_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Skipping test for 'libc.src.strings.bcmp_x86_64_opt_avx512' insufficient host cpu features 'AVX512BW'
-- Skipping test for 'libc.src.strings.bzero_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Configuring done
-- Generating done
-- Build files have been written to: /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins
[4/5] cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins && /usr/bin/cmake --build /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/ --target check-libc --config Debug
[0/1] Running libc tests via lit
-- Testing: 3830 tests, 32 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.
FAIL: libc :: src/sys/statfs/linux/libc.test.src.sys.statfs.linux.statfs_test.__build__ (2869 of 3830)
******************** TEST 'libc :: src/sys/statfs/linux/libc.test.src.sys.statfs.linux.statfs_test.__build__' FAILED ********************
[==========] Running 2 tests from 1 test suite.
[ RUN      ] LlvmLibcSysStatfsTest.StatfsBasic
[       OK ] LlvmLibcSysStatfsTest.StatfsBasic (12 us)
[ RUN      ] LlvmLibcSysStatfsTest.StatfsInvalidPath
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/src/sys/statfs/linux/statfs_test.cpp:53: FAILURE
Failed to match LIBC_NAMESPACE::rmdir(TEST_DIR) against Succeeds(0).
Expected return value to be equal to 0 but got -1.
Expected errno to be equal to 0(0) but got ENOENT(2).
[  FAILED  ] LlvmLibcSysStatfsTest.StatfsInvalidPath
Ran 2 tests.  PASS: 1  FAIL: 1

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
********************
Failed Tests (1):
  libc :: src/sys/statfs/linux/libc.test.src.sys.statfs.linux.statfs_test.__build__


Testing Time: 3.53s

Total Discovered Tests: 3830
  Passed: 3829 (99.97%)
  Failed:    1 (0.03%)
FAILED: libc/test/CMakeFiles/check-libc /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/libc/test/CMakeFiles/check-libc 
cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/libc/test && /usr/bin/python3 /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/./bin/llvm-lit -sv /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/libc/test
ninja: build stopped: subcommand failed.
FAILED: runtimes/CMakeFiles/check-libc /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/CMakeFiles/check-libc 
cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins && /usr/bin/cmake --build /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/ --target check-libc --config Debug
ninja: build stopped: subcommand failed.
['ninja', 'check-libc'] exited with return code 1.
The build step threw an exception...
Traceback (most recent call last):
  File "/home/llvm-libc-buildbot/home/sivachandra/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 181, in step
    yield
  File "/home/llvm-libc-buildbot/home/sivachandra/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 151, in main
    run_command(['ninja', 'check-libc'])
  File "/home/llvm-libc-buildbot/home/sivachandra/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 196, in run_command
Step 7 (check-libc) failure: check-libc (failure)
...
-- Skipping test for 'libc.src.string.memset_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Skipping test for 'libc.src.strings.bcmp_x86_64_opt_avx512' insufficient host cpu features 'AVX512BW'
-- Skipping test for 'libc.src.strings.bzero_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Configuring done
-- Generating done
-- Build files have been written to: /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins
[4/5] cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins && /usr/bin/cmake --build /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/ --target check-libc --config Debug
[0/1] Running libc tests via lit
-- Testing: 3830 tests, 32 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.
FAIL: libc :: src/sys/statfs/linux/libc.test.src.sys.statfs.linux.statfs_test.__build__ (2869 of 3830)
******************** TEST 'libc :: src/sys/statfs/linux/libc.test.src.sys.statfs.linux.statfs_test.__build__' FAILED ********************
[==========] Running 2 tests from 1 test suite.
[ RUN      ] LlvmLibcSysStatfsTest.StatfsBasic
[       OK ] LlvmLibcSysStatfsTest.StatfsBasic (12 us)
[ RUN      ] LlvmLibcSysStatfsTest.StatfsInvalidPath
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/src/sys/statfs/linux/statfs_test.cpp:53: FAILURE
Failed to match LIBC_NAMESPACE::rmdir(TEST_DIR) against Succeeds(0).
Expected return value to be equal to 0 but got -1.
Expected errno to be equal to 0(0) but got ENOENT(2).
[  FAILED  ] LlvmLibcSysStatfsTest.StatfsInvalidPath
Ran 2 tests.  PASS: 1  FAIL: 1

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
********************
Failed Tests (1):
  libc :: src/sys/statfs/linux/libc.test.src.sys.statfs.linux.statfs_test.__build__


Testing Time: 3.53s

Total Discovered Tests: 3830
  Passed: 3829 (99.97%)
  Failed:    1 (0.03%)
FAILED: libc/test/CMakeFiles/check-libc /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/libc/test/CMakeFiles/check-libc 
cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/libc/test && /usr/bin/python3 /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/./bin/llvm-lit -sv /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/libc/test
ninja: build stopped: subcommand failed.
FAILED: runtimes/CMakeFiles/check-libc /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/CMakeFiles/check-libc 
cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins && /usr/bin/cmake --build /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/ --target check-libc --config Debug
ninja: build stopped: subcommand failed.
['ninja', 'check-libc'] exited with return code 1.
The build step threw an exception...
Traceback (most recent call last):
  File "/home/llvm-libc-buildbot/home/sivachandra/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 181, in step
    yield
  File "/home/llvm-libc-buildbot/home/sivachandra/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 151, in main
    run_command(['ninja', 'check-libc'])
  File "/home/llvm-libc-buildbot/home/sivachandra/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 196, in run_command

```

</details>

https://github.com/llvm/llvm-project/pull/216241