Merge pull request #2131 from WalterBright/Tzero

object.d: no 0 size structs for AAs
merged-on-behalf-of: Sebastian Wilzbach <sebi.wilzbach@gmail.com>

Author: dlang-bot

src/object.d

@@ -2264,6 +2264,7 @@ unittest
 {
     static struct T
     {
+        byte b;
         static size_t count;
         this(this) { ++count; }
     }