Intel oneAPI fails to compile stdlib on OSX

[awvwgk]

We encounter an ICE with Intel oneAPI on OSX when compiling the tests:

[ 75%] Building Fortran object src/tests/stats/CMakeFiles/test_varn.dir/test_varn.f90.o
cd /Users/runner/work/stdlib/stdlib/build/src/tests/stats && /opt/intel/oneapi/compiler/2021.1.1/mac/bin/intel64/ifort  -I/Users/runner/work/stdlib/stdlib/build/src/mod_files -O3 -warn declarations,general,usage,interfaces,unused -standard-semantics -stand f18 -c /Users/runner/work/stdlib/stdlib/src/tests/stats/test_varn.f90 -o CMakeFiles/test_varn.dir/test_varn.f90.o
/Users/runner/work/stdlib/stdlib/src/tests/stats/test_varn.f90: catastrophic error: **Internal compiler error: segmentation violation signal raised** Please report this error along with the circumstances in which it occurred in a Software Problem Report.  Note: File and line given may not be explicit cause of this error.
compilation aborted for /Users/runner/work/stdlib/stdlib/src/tests/stats/test_varn.f90 (code 1)

Maybe a Mac user with access to Intel compilers can help to pin down this issue.

See #367 for the workflow triggering this ICE.

[awvwgk]

This is apparently again related to -standard-semantics, easiest fix is to drop this flag as discussed in #298.