Fix PR23045.

Keep a note in the materializer that we are stripping debug info so that
user doing a lazy read of the module don't hit outdated formats.

Thanks to Duncan for suggesting the fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233603 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-link/llvm-link.cpp

@@ -15,6 +15,7 @@
 #include "llvm/Linker/Linker.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/LLVMContext.h"
@@ -69,11 +70,8 @@ loadFile(const char *argv0, const std::string &FN, LLVMContext &Context) {
   if (!Result)
     Err.print(argv0, errs());
 
-  // Fixme (pr23045). We would like to upgrade the metadata with something like
-  //  Result->materializeMetadata();
-  //  UpgradeDebugInfo(*Result);
-  // but that fails to drop old debug info from function bodies.
-  Result->materializeAllPermanently();
+  Result->materializeMetadata();
+  UpgradeDebugInfo(*Result);
 
   return Result;
 }