[StaticAnalyzer] Remove several unused declarations

The function definition of GenerateAutoTransition was removed by:

  commit b1d3d96
  Author: Anna Zaks <ganna@apple.com>
  Date:   Thu Oct 27 00:59:23 2011 +0000

The function definitions of enqueueEndOfPath and GenerateCallExitNode
were removed by:

  commit 0ec04bf
  Author: Anna Zaks <ganna@apple.com>
  Date:   Thu Oct 27 00:59:28 2011 +0000

clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h

@@ -239,11 +239,6 @@ class ExprEngine {
     return {blockPtr, currStmtIdx};
   }
 
-  void GenerateAutoTransition(ExplodedNode *N);
-  void enqueueEndOfPath(ExplodedNodeSet &S);
-  void GenerateCallExitNode(ExplodedNode *N);
-
-
   /// Dump graph to the specified filename.
   /// If filename is empty, generate a temporary one.
   /// \return The filename the graph is written into.