Address review feedback for r228003.
- use named constructors
- get rid of MarkAsPrologue

llvm-svn: 228021
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index 406afb2..28f7449 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -770,7 +770,7 @@
 
   // Save the current IR generation state.
   CGBuilderTy::InsertPoint savedIP = Builder.saveAndClearIP();
-  ApplyDebugLocation AL(*this, ApplyDebugLocation::Artificial, CurEHLocation);
+  auto DL = ApplyDebugLocation::CreateDefaultArtificial(*this, CurEHLocation);
 
   const EHPersonality &personality = EHPersonality::get(CGM);