Port from qAsConst() to std::as_const()

We've been requiring C++17 since Qt 6.0, and our qAsConst use finally
starts to bother us (QTBUG-99313), so time to port away from it
now.

Since qAsConst has exactly the same semantics as std::as_const (down
to rvalue treatment, constexpr'ness and noexcept'ness), there's really
nothing more to it than a global search-and-replace.

Task-number: QTBUG-99313
Change-Id: I88edd91395849574436299b8badda21bb93bea39
Reviewed-by: hjk <hjk@qt.io>

src/plugins/coreplugin/modemanager.cpp

@@ -189,7 +189,7 @@ void ModeManagerPrivate::extensionsInitializedHelper()
     Utils::sort(m_modes, &IMode::priority);
     std::reverse(m_modes.begin(), m_modes.end());
 
-    for (IMode *mode : qAsConst(m_modes))
+    for (IMode *mode : std::as_const(m_modes))
         appendMode(mode);
 
     if (m_pendingFirstActiveMode.isValid())
@@ -279,7 +279,7 @@ void ModeManager::addAction(QAction *action, int priority)
 
     // Count the number of commands with a higher priority
     int index = 0;
-    for (int p : qAsConst(d->m_actions)) {
+    for (int p : std::as_const(d->m_actions)) {
         if (p > priority)
             ++index;
     }