Reduce meta-data object sizes, introduce meta-data helper classes.

Change-Id: Id14ad218f1c74c659701352fdf1a45bf6444daa3
diff --git a/src/primitive.h b/src/primitive.h
index 5d41966..402a2b5 100644
--- a/src/primitive.h
+++ b/src/primitive.h
@@ -101,11 +101,13 @@
       case kPrimInt:
         return 'I';
       case kPrimFloat:
-        return 'J';
+        return 'F';
       case kPrimLong:
         return 'J';
       case kPrimDouble:
         return 'D';
+      case kPrimVoid:
+        return 'V';
       default:
         LOG(FATAL) << "Primitive char conversion on invalid type " << static_cast<int>(type);
         return 0;