ProjectExplorer Nodes: Replace dynamic_cast with as* functions

The OS X linker makes using dynamic_casts across shared object
boundaries fail, so do all casting in the projectexplorer library
and provide functions to do it.

Task-number: QTCREATORBUG-13864
Change-Id: I0e13c0986f8342d83c3b838ffdd2dd7b8312b13c
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/projectexplorer/projectnodes.cpp

@@ -198,6 +198,26 @@ void Node::emitNodeUpdated()
         ProjectTree::instance()->emitNodeUpdated(this);
 }
 
+FileNode *Node::asFileNode()
+{
+    return 0;
+}
+
+FolderNode *Node::asFolderNode()
+{
+    return 0;
+}
+
+ProjectNode *Node::asProjectNode()
+{
+    return 0;
+}
+
+SessionNode *Node::asSessionNode()
+{
+    return 0;
+}
+
 void Node::setParentFolderNode(FolderNode *parentFolder)
 {
     m_folderNode = parentFolder;
@@ -235,6 +255,11 @@ bool FileNode::isGenerated() const
     return m_generated;
 }
 
+FileNode *FileNode::asFileNode()
+{
+    return this;
+}
+
 /*!
   \class ProjectExplorer::FolderNode
 
@@ -494,6 +519,11 @@ void FolderNode::removeFolderNodes(const QList<FolderNode*> &subFolders)
     ProjectTree::instance()->emitFoldersRemoved(this);
 }
 
+FolderNode *FolderNode::asFolderNode()
+{
+    return this;
+}
+
 bool FolderNode::showInSimpleTree() const
 {
     return false;
@@ -672,6 +702,11 @@ void ProjectNode::removeProjectNodes(const QList<ProjectNode*> &subProjects)
     }
 }
 
+ProjectNode *ProjectNode::asProjectNode()
+{
+    return this;
+}
+
 
 /*!
   \class ProjectExplorer::SessionNode
@@ -707,6 +742,11 @@ void SessionNode::projectDisplayNameChanged(Node *node)
     ProjectTree::instance()->emitNodeSortKeyChanged(node);
 }
 
+SessionNode *SessionNode::asSessionNode()
+{
+    return this;
+}
+
 QList<ProjectNode*> SessionNode::projectNodes() const
 {
     return m_projectNodes;