Index: include/llvm/Transforms/IPO/FunctionImport.h
===================================================================
--- include/llvm/Transforms/IPO/FunctionImport.h
+++ include/llvm/Transforms/IPO/FunctionImport.h
@@ -53,9 +53,7 @@
       : Index(Index), ModuleLoader(std::move(ModuleLoader)) {}
 
   /// Import functions in Module \p M based on the supplied import list.
-  Expected<bool> importFunctions(
-      Module &M, const ImportMapTy &ImportList,
-      Optional<std::function<void(Module &)>> PostBitcodeLoading = None);
+  Expected<bool> importFunctions(Module &M, const ImportMapTy &ImportList);
 
 private:
   /// The summaries index used to trigger importing.
Index: lib/LTO/ThinLTOCodeGenerator.cpp
===================================================================
--- lib/LTO/ThinLTOCodeGenerator.cpp
+++ lib/LTO/ThinLTOCodeGenerator.cpp
@@ -201,8 +201,7 @@
   };
 
   FunctionImporter Importer(Index, Loader);
-  Expected<bool> Result =
-      Importer.importFunctions(TheModule, ImportList, {verifyLoadedModule});
+  Expected<bool> Result = Importer.importFunctions(TheModule, ImportList);
   if (!Result) {
     handleAllErrors(Result.takeError(), [&](ErrorInfoBase &EIB) {
       SMDiagnostic Err = SMDiagnostic(TheModule.getModuleIdentifier(),
@@ -211,6 +210,8 @@
     });
     report_fatal_error("importFunctions failed");
   }
+  // Verify again after cross-importing.
+  verifyLoadedModule(TheModule);
 }
 
 static void optimizeModule(Module &TheModule, TargetMachine &TM,
Index: lib/Transforms/IPO/FunctionImport.cpp
===================================================================
--- lib/Transforms/IPO/FunctionImport.cpp
+++ lib/Transforms/IPO/FunctionImport.cpp
@@ -646,8 +646,7 @@
 // index.
 //
 Expected<bool> FunctionImporter::importFunctions(
-    Module &DestModule, const FunctionImporter::ImportMapTy &ImportList,
-    Optional<std::function<void(Module &)>> PostBitcodeLoading) {
+    Module &DestModule, const FunctionImporter::ImportMapTy &ImportList) {
   DEBUG(dbgs() << "Starting import for Module "
                << DestModule.getModuleIdentifier() << "\n");
   unsigned ImportedCount = 0;
@@ -755,8 +754,6 @@
     // Upgrade debug info after we're done materializing all the globals and we
     // have loaded all the required metadata!
     UpgradeDebugInfo(*SrcModule);
-    if (PostBitcodeLoading)
-      (*PostBitcodeLoading)(*SrcModule);
 
     // Link in the specified functions.
     if (renameModuleForThinLTO(*SrcModule, Index, &GlobalsToImport))