Port QtCreator over to use filterRegularExpression

QSortFilterProxyModel::filterRegExp is going to go away in Qt6,
so port over to use QRegularExpression instead.

This required some changes where setFilterWildcard/FixedString()
was being used, as those would instantiate QRegExp based filters
in Qt 5, and will use QRegularExpression in Qt 6. Use the generic
setFilterRegularExpression here, to keep things portable between
5 and 6.

Change-Id: I6379be781aa3821b10ba783c088f82c1a0970911
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/coreplugin/dialogs/ioptionspage.cpp

@@ -36,6 +36,7 @@
 #include <QIcon>
 #include <QLabel>
 #include <QPushButton>
+#include <QRegularExpression>
 
 using namespace Utils;
 
@@ -227,11 +228,11 @@ const QList<Core::IOptionsPage *> Core::IOptionsPage::allOptionsPages()
 }
 
 /*!
-    Is used by the \uicontrol Options dialog search filter to match \a searchKeyWord to this options
+    Is used by the \uicontrol Options dialog search filter to match \a regexp to this options
     page. This defaults to take the widget and then looks for all child labels, check boxes, push
     buttons, and group boxes. Should return \c true when a match is found.
 */
-bool Core::IOptionsPage::matches(const QString &searchKeyWord) const
+bool Core::IOptionsPage::matches(const QRegularExpression &regexp) const
 {
     if (!m_keywordsInitialized) {
         auto that = const_cast<IOptionsPage *>(this);
@@ -251,7 +252,7 @@ bool Core::IOptionsPage::matches(const QString &searchKeyWord) const
         m_keywordsInitialized = true;
     }
     foreach (const QString &keyword, m_keywords)
-        if (keyword.contains(searchKeyWord, Qt::CaseInsensitive))
+        if (keyword.contains(regexp))
             return true;
     return false;
 }