Subzero: Prune unreachable nodes after constructing the Cfg.

src/IceCfg.h

 //===- subzero/src/IceCfg.h - Control flow graph ----------------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the Cfg class, which represents the control flow
@@ skipping 117 matching lines @@
     return static_cast<T *>(TargetAssembler.get());
   }
   Assembler *releaseAssembler() { return TargetAssembler.release(); }
   bool hasComputedFrame() const;
   bool getFocusedTiming() const { return FocusedTiming; }
   void setFocusedTiming() { FocusedTiming = true; }
 
   // Passes over the CFG.
   void translate();
   // After the CFG is fully constructed, iterate over the nodes and
-  // compute the predecessor edges, in the form of
-  // CfgNode::InEdges[].
-  void computePredecessors();
+  // compute the predecessor and successor edges, in the form of
+  // CfgNode::InEdges[] and CfgNode::OutEdges[].
+  void computeInOutEdges();
   void renumberInstructions();
   void placePhiLoads();
   void placePhiStores();
   void deletePhis();
   void advancedPhiLowering();
   void reorderNodes();
   void doAddressOpt();
   void doArgLowering();
   void doNopInsertion();
   void genCode();
@@ skipping 71 matching lines @@
   // other uses are possible.
   ICE_TLS_DECLARE_FIELD(const Cfg *, CurrentCfg);
 
 public:
   static void TlsInit() { ICE_TLS_INIT_FIELD(CurrentCfg); }
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICECFG_H