DebugInfo: don't require full definitions for friend classes

Fixes a crash-on-valid introduced by r188486 (which should've occurred
earlier but for a blatant bug where calling createFwdDecl from the
requireCompleteType callback was useless under -flimit-debug-info and we
were just getting lucky with other later callbacks requiring the type
anyway).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188622 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index e6e12e4..71253ca 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1136,9 +1136,8 @@
     if ((*BI)->isUnsupportedFriend())
       continue;
     if (TypeSourceInfo *TInfo = (*BI)->getFriendType())
-      EltTys.push_back(DBuilder.createFriend(RecordTy,
-                                             getOrCreateType(TInfo->getType(),
-                                                             Unit)));
+      EltTys.push_back(DBuilder.createFriend(
+          RecordTy, getOrCreateType(TInfo->getType(), Unit, true)));
   }
 }