Index: llvm/trunk/include/llvm/Target/TargetLoweringObjectFile.h
===================================================================
--- llvm/trunk/include/llvm/Target/TargetLoweringObjectFile.h
+++ llvm/trunk/include/llvm/Target/TargetLoweringObjectFile.h
@@ -38,7 +38,7 @@
   MCContext *Ctx;
 
   /// Name-mangler for global names.
-  Mangler *Mang;
+  Mangler *Mang = nullptr;
 
   TargetLoweringObjectFile(
     const TargetLoweringObjectFile&) = delete;
Index: llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp
===================================================================
--- llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp
+++ llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp
@@ -43,6 +43,8 @@
 void TargetLoweringObjectFile::Initialize(MCContext &ctx,
                                           const TargetMachine &TM) {
   Ctx = &ctx;
+  // `Initialize` can be called more than once.
+  if (Mang != nullptr) delete Mang;
   Mang = new Mangler();
   InitMCObjectFileInfo(TM.getTargetTriple(), TM.isPositionIndependent(),
                        TM.getCodeModel(), *Ctx);