Avoid round trip to NSString to decrease excessive memory consumption for performance tests with a factor of 100x (the string leaked, could perhaps be fixed differently, but this fix seems good).
Avoid round trip to NSString to decrease excessive memory consumption for performance tests with a factor of 100x (the string leaked, could perhaps be fixed differently, but this fix seems good).

Benchmark results when running Eager run only, 1M iterations

Before optimization, peak RAM usage 650MB at end of test
After optimization, peak RAM usage 6,3MB at end of test

Performance before:
=================================
23545 ms encode
3222 ms decode
1183 ms use
1642 ms dealloc
6047 ms decode+use+dealloc
=================================

Performance after:
=================================
20589 ms encode
2681 ms decode
1002 ms use
1446 ms dealloc
5128 ms decode+use+dealloc
=================================

hassila/FlatBuffersSwift,hassila/FlatBuffersSwift,mzaks/FlatBuffersSwift,mzaks/FlatBuffersSwift