Use llvm_unreachable instead of assert(0)

llvm-svn: 196971
diff --git a/llvm/lib/Target/R600/SIAnnotateControlFlow.cpp b/llvm/lib/Target/R600/SIAnnotateControlFlow.cpp
index 9c0feff..5240c48 100644
--- a/llvm/lib/Target/R600/SIAnnotateControlFlow.cpp
+++ b/llvm/lib/Target/R600/SIAnnotateControlFlow.cpp
@@ -253,7 +253,7 @@
     PhiInserter.AddAvailableValue(Parent, Ret);
 
   } else {
-    assert(0 && "Unhandled loop condition!");
+    llvm_unreachable("Unhandled loop condition!");
   }
 }