generate size-prefixed monster binary as well

tests/generate_code.sh

@@ -15,6 +15,7 @@
 # limitations under the License.
 
 ../flatc --cpp --java --csharp --go --binary --python --js --ts --php --grpc --gen-mutable --reflect-names --gen-object-api --no-includes --cpp-ptr-type flatbuffers::unique_ptr  --no-fb-import -I include_test monster_test.fbs monsterdata_test.json
+../flatc -b --prefix-size -I include_test monster_test_ps.fbs monsterdata_test.json
 ../flatc --cpp --java --csharp --go --binary --python --js --ts --php --gen-mutable --reflect-names --no-fb-import --cpp-ptr-type flatbuffers::unique_ptr  -o namespace_test namespace_test/namespace_test1.fbs namespace_test/namespace_test2.fbs
 ../flatc --cpp --js --ts --php --gen-mutable --reflect-names --gen-object-api --cpp-ptr-type flatbuffers::unique_ptr -o union_vector ./union_vector/union_vector.fbs
 ../flatc -b --schema --bfbs-comments -I include_test monster_test.fbs

tests/monster_test_ps.fbs

@@ -0,0 +1,10 @@
+// similar schema, except to be parsed with --prefix-size
+
+include "monster_test.fbs";
+
+namespace MyGame.Example;
+
+root_type Monster;
+
+file_identifier "MONS";
+file_extension "mops";