LLVM Buildbot failure on openmp runtime test (#143674)
Error looks to be missing includes for complex number support in some
system. Removing test for now.
Relevant PR :
[PR-134709](https://github.com/llvm/llvm-project/pull/134709)
```
.---command stderr------------
# | /home/uweigand/sandbox/buildbot/openmp-s390x-linux/llvm.src/openmp/runtime/test/worksharing/for/omp_for_private_reduction.cpp:78:42: error: use of undeclared identifier 'I'
# | 78 | double _Complex expected = 0.0 + 0.0 * I;
# | | ^
# | /home/uweigand/sandbox/buildbot/openmp-s390x-linux/llvm.src/openmp/runtime/test/worksharing/for/omp_for_private_reduction.cpp:79:40: error: use of undeclared identifier 'I'
# | 79 | double _Complex result = 0.0 + 0.0 * I;
# | | ^
# | /home/uweigand/sandbox/buildbot/openmp-s390x-linux/llvm.src/openmp/runtime/test/worksharing/for/omp_for_private_reduction.cpp:84:22: error: use of undeclared identifier 'I'
# | 84 | arr[i] = i - i * I;
# | | ^
# | /home/uweigand/sandbox/buildbot/openmp-s390x-linux/llvm.src/openmp/runtime/test/worksharing/for/omp_for_private_reduction.cpp:92:19: error: use of undeclared identifier 'creal'
# | 92 | real_sum += creal(arr[i]);
# | | ^~~~~
# | /home/uweigand/sandbox/buildbot/openmp-s390x-linux/llvm.src/openmp/runtime/test/worksharing/for/omp_for_private_reduction.cpp:93:19: error: use of undeclared identifier 'cimag'
# | 93 | imag_sum += cimag(arr[i]);
# | | ^~~~~
# | /home/uweigand/sandbox/buildbot/openmp-s390x-linux/llvm.src/openmp/runtime/test/worksharing/for/omp_for_private_reduction.cpp:96:36: error: use of undeclared identifier 'I'
# | 96 | result = real_sum + imag_sum * I;
# | | ^
# | /home/uweigand/sandbox/buildbot/openmp-s390x-linux/llvm.src/openmp/runtime/test/worksharing/for/omp_for_private_reduction.cpp:97:9: error: use of undeclared identifier 'cabs'
# | 97 | if (cabs(result - expected) > 1e-6) {
# | | ^~~~
# | 7 errors generated.
```
Co-authored-by: Chandra Ghale <ghale@pe31.hpc.amslabs.hpecorp.net>
