codemod cases of string to class conversion (6/7)

Summary: `phps ClassnameToClassCodemod --try-cn-to-cls --cn-to-cls --specific-dir` on directories flib/realtime through flib/thrift

Reviewed By: vassilmladenov

Differential Revision: D70997958

fbshipit-source-id: 23412d8559c94b98c230015e33d519f2b76e9cea

Author: Millie Chen

thrift/lib/hack/src/protocol/ThriftSerializationHelper.php

@@ -339,7 +339,7 @@ public static function readStructHelper(
         break;
       case TType::STRUCT:
         $cls = Shapes::at($tspec, 'class');
-        $struct = new $cls();
+        $struct = HH_FIXME::tryClassnameToClass($cls) |> new $$();
         $xfer += PHPism_FIXME::castForArithmetic($struct->read($protocol));
         $object = $struct;
         break;