Index: lib/CodeGen/CGDebugInfo.h
===================================================================
--- lib/CodeGen/CGDebugInfo.h
+++ lib/CodeGen/CGDebugInfo.h
@@ -308,6 +308,7 @@
   ~CGDebugInfo();
 
   void finalize();
+  void finalizeSP(llvm::DISubprogram *SP) { DBuilder.finalizeSP(SP); }
 
   /// Module debugging: Support for building PCMs.
   /// @{
Index: lib/CodeGen/CGVTables.cpp
===================================================================
--- lib/CodeGen/CGVTables.cpp
+++ lib/CodeGen/CGVTables.cpp
@@ -152,6 +152,12 @@
   llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty, /*ForVTable=*/true);
   llvm::Function *BaseFn = cast<llvm::Function>(Callee);
 
+  // We may not clone a subprogram that contains temporary metadata, so finalize
+  // it now - we will not be modifying it.
+  if (CGDebugInfo *DI = CGM.getModuleDebugInfo())
+    if (llvm::DISubprogram *SP = BaseFn->getSubprogram())
+      DI->finalizeSP(SP);
+
   // Clone to thunk.
   llvm::ValueToValueMapTy VMap;
   llvm::Function *NewFn = llvm::CloneFunction(BaseFn, VMap);