Add Parse/Sema support for weak_import attribute.
 - Also, diagnose weak applied to types.

llvm-svn: 66259
diff --git a/clang/lib/Parse/AttributeList.cpp b/clang/lib/Parse/AttributeList.cpp
index 6b58a00..9cee6ab 100644
--- a/clang/lib/Parse/AttributeList.cpp
+++ b/clang/lib/Parse/AttributeList.cpp
@@ -105,6 +105,7 @@
       return IgnoredAttribute; // FIXME: printf format string checking.
     break;
   case 11:
+    if (!memcmp(Str, "weak_import", 11)) return AT_weak_import;
     if (!memcmp(Str, "vector_size", 11)) return AT_vector_size;
     if (!memcmp(Str, "constructor", 11)) return AT_constructor;
     if (!memcmp(Str, "unavailable", 11)) return AT_unavailable;