The patch disallows any platform specific code in sys_util_core and
doesn't let sys_util compile on windows platform.
This ensure to some extent that we keep sys_util and it's dependency
sys_util_core independent of windows code.
check_code_hygiene is not foolproof.
Test: Ran the script against a modified file in sys_util_core containing
string "target_os = "
Tried to compile sys_util on windows.
Bug: b:215610772
Upstream-Crate: common/win_sys_util
Cq-Depend: chromium:3433709
Change-Id: Ideb45092a959dd347d966633c3bd4e82f842b1a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3438709
Reviewed-by: Dennis Kempin <denniskempin@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
