Fix misaligned DeclGroup allocation.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162069 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/DeclGroup.h b/include/clang/AST/DeclGroup.h
index 63cdac5..cda6ae5 100644
--- a/include/clang/AST/DeclGroup.h
+++ b/include/clang/AST/DeclGroup.h
@@ -26,7 +26,11 @@
 
 class DeclGroup {
   // FIXME: Include a TypeSpecifier object.
-  unsigned NumDecls;
+  union {
+    unsigned NumDecls;
+
+    Decl *Aligner;
+  };
 
 private:
   DeclGroup() : NumDecls(0) {}