Utils: More explicit host os use to make it stand out

Quite a few of the uses are actually wrong, but are better visible
now and therefore more likely to be fixed.

Change-Id: Ia51f7d6eb1b2d3a9c9f73d67dabacfd227c44b15
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/clangtools/clangtoolsutils.cpp

@@ -284,7 +284,7 @@ static QStringList extraOptions(const QString &envVar)
     if (!qtcEnvironmentVariableIsSet(envVar))
         return QStringList();
     QString arguments = qtcEnvironmentVariable(envVar);
-    return Utils::ProcessArgs::splitArgs(arguments);
+    return ProcessArgs::splitArgs(arguments, HostOsInfo::hostOs());
 }
 
 QStringList extraClangToolsPrependOptions()