Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64"

It broke; LLVM :: CodeGen__Generic__2009-11-16-BadKillsCrash.ll

llvm-svn: 249032
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index a48de57..72af276 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2205,7 +2205,10 @@
                           getValue(I.getAddress())));
 }
 
-void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {}
+void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {
+  if (DAG.getTarget().Options.TrapUnreachable)
+    DAG.setRoot(DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot()));
+}
 
 void SelectionDAGBuilder::visitFSub(const User &I) {
   // -0.0 - X --> fneg