Add getAsLoopNode() method for Loop node

glslang/Include/intermediate.h

@@ -790,6 +790,7 @@ class TIntermBranch;
 class TIntermTyped;
 class TIntermMethod;
 class TIntermSymbol;
+class TIntermLoop;
 
 } // end namespace glslang
 
@@ -817,6 +818,7 @@ public:
     virtual       glslang::TIntermMethod*        getAsMethodNode()          { return 0; }
     virtual       glslang::TIntermSymbol*        getAsSymbolNode()          { return 0; }
     virtual       glslang::TIntermBranch*        getAsBranchNode()          { return 0; }
+	virtual       glslang::TIntermLoop*          getAsLoopNode()            { return 0; }
 
     virtual const glslang::TIntermTyped*         getAsTyped()         const { return 0; }
     virtual const glslang::TIntermOperator*      getAsOperator()      const { return 0; }
@@ -829,6 +831,7 @@ public:
     virtual const glslang::TIntermMethod*        getAsMethodNode()    const { return 0; }
     virtual const glslang::TIntermSymbol*        getAsSymbolNode()    const { return 0; }
     virtual const glslang::TIntermBranch*        getAsBranchNode()    const { return 0; }
+	virtual const glslang::TIntermLoop*          getAsLoopNode()      const { return 0; }
     virtual ~TIntermNode() { }
 
 protected:
@@ -910,6 +913,8 @@ public:
         control(ELoopControlNone)
     { }
 
+	virtual       TIntermLoop* getAsLoopNode() { return this; }
+	virtual const TIntermLoop* getAsLoopNode() const { return this; }
     virtual void traverse(TIntermTraverser*);
     TIntermNode*  getBody() const { return body; }
     TIntermTyped* getTest() const { return test; }