run_unittests: assume that on windows that intel means icl

There actually is an ICC for windows that can be used to cross compile
from Windows to Linux, but it's not supported in meson currently and I
don't plan to enable it.

run_unittests.py

@@ -5867,6 +5867,10 @@ class NativeFileTests(BasePlatformTests):
                 raise unittest.SkipTest('No alternate Fortran implementation.')
             elif comp.id == 'gcc':
                 if shutil.which('ifort'):
+                    # There is an ICC for windows (windows build, linux host),
+                    # but we don't support that ATM so lets not worry about it.
+                    if is_windows():
+                        return 'ifort', 'intel-cl'
                     return 'ifort', 'intel'
                 elif shutil.which('flang'):
                     return 'flang', 'flang'