Stop emitting lifetime region info when stack coloring is not enabled in O0

- this should fix PR13780



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163370 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index b587884..1eb251d 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5218,6 +5218,12 @@
   }
   case Intrinsic::lifetime_start:
   case Intrinsic::lifetime_end: {
+    // Stack coloring is not enabled in O0, discard region information.
+    if (TM.getOptLevel() == CodeGenOpt::None) {
+      if (Intrinsic == Intrinsic::lifetime_start)
+        setValue(&I, DAG.getUNDEF(TLI.getPointerTy()));
+      return 0;
+    }
     SDValue Ops[2];
     AllocaInst *LifetimeObject =dyn_cast_or_null<AllocaInst>(
                                    GetUnderlyingObject(I.getArgOperand(1), TD));