[modules] Allow emission of update records for predefined __va_list_tag.
Handles the cases where old __va_list_tag is coming from a module and the new
is not, needing an update record.
Fixes https://llvm.org/bugs/show_bug.cgi?id=27890
Patch by Cristina Cristescu, Richard Smith and me.
llvm-svn: 273159
diff --git a/clang/test/Modules/pr27890.cpp b/clang/test/Modules/pr27890.cpp
new file mode 100644
index 0000000..8bb9a9f
--- /dev/null
+++ b/clang/test/Modules/pr27890.cpp
@@ -0,0 +1,9 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -std=c++11 -I%S/Inputs/PR27890 -verify %s
+// RUN: %clang_cc1 -std=c++11 -fmodules -fmodule-map-file=%S/Inputs/PR27890/module.modulemap -fmodules-cache-path=%t -I%S/Inputs/PR27890 -verify %s
+
+#include "a.h"
+enum ActionType {};
+opt<ActionType> a(values(""));
+
+// expected-no-diagnostics
\ No newline at end of file