Subzero: Prune unreachable nodes after constructing the Cfg.

src/IceConverter.cpp

 //===- subzero/src/IceConverter.cpp - Converts LLVM to Ice  ---------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the LLVM to ICE converter.
@@ skipping 95 matching lines @@
 
     // Make an initial pass through the block list just to resolve the
     // blocks in the original linearized order.  Otherwise the ICE
     // linearized order will be affected by branch targets in
     // terminator instructions.
     for (const BasicBlock &BBI : *F)
       mapBasicBlockToNode(&BBI);
     for (const BasicBlock &BBI : *F)
       convertBasicBlock(&BBI);
     Func->setEntryNode(mapBasicBlockToNode(&F->getEntryBlock()));
-    Func->computePredecessors();
+    Func->computeInOutEdges();
 
     Ice::Cfg::setCurrentCfg(nullptr);
     Converter.translateFcn(std::move(Func));
   }
 
   // convertConstant() does not use Func or require it to be a valid
   // Ice::Cfg pointer.  As such, it's suitable for e.g. constructing
   // global initializers.
   Ice::Constant *convertConstant(const Constant *Const) {
     if (const auto GV = dyn_cast<GlobalValue>(Const)) {
@@ skipping 775 matching lines @@
       Ctx->pushTimer(TimerID, StackID);
     }
     LLVM2ICEFunctionConverter FunctionConverter(*this);
     FunctionConverter.convertFunction(&I);
     if (TimeThisFunction)
       Ctx->popTimer(TimerID, StackID);
   }
 }
 
 } // end of namespace Ice