ProjectExplorer: Don't display alien dir separators on Windows

In case you opened more than one project with the same name, it shows
the full path incl. dir separators in the first-level tabs in the
project mode.

Change-Id: Idbf5dfe6ef0c20eecf3a3473011bb2d9b1794cea
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/projectexplorer/doubletabwidget.cpp

@@ -35,6 +35,7 @@
 #include <utils/stylehelper.h>
 #include <utils/theme/theme.h>
 
+#include <QDir>
 #include <QRect>
 #include <QPainter>
 #include <QMouseEvent>
@@ -573,3 +574,8 @@ bool DoubleTabWidget::event(QEvent *event)
     }
     return QWidget::event(event);
 }
+
+QString DoubleTabWidget::Tab::displayName() const
+{
+    return nameIsUnique ? name : QDir::toNativeSeparators(fullName);
+}

src/plugins/projectexplorer/doubletabwidget.h

@@ -80,9 +80,7 @@ private:
         bool nameIsUnique;
         QStringList subTabs;
         int currentSubTab;
-        QString displayName() const {
-            return nameIsUnique ? name : fullName;
-        }
+        QString displayName() const;
     };
     void updateNameIsUniqueAdd(Tab *tab);
     void updateNameIsUniqueRemove(const Tab &tab);