Don't special case one line extern "C" decls.

We already avoided warning for

extern "C" const char *Version_string = "2.9";

now we also don't produce any warnings for

extern "C" {
  extern const char *Version_string2 = "2.9";
}

llvm-svn: 178333
diff --git a/clang/test/SemaCXX/linkage-spec.cpp b/clang/test/SemaCXX/linkage-spec.cpp
index cb7e32c..0ba9508 100644
--- a/clang/test/SemaCXX/linkage-spec.cpp
+++ b/clang/test/SemaCXX/linkage-spec.cpp
@@ -90,6 +90,10 @@
 // PR7076
 extern "C" const char *Version_string = "2.9";
 
+extern "C" {
+  extern const char *Version_string2 = "2.9";
+}
+
 namespace PR9162 {
   extern "C" {
     typedef struct _ArtsSink ArtsSink;