The modification introduces an overhead of 1.5% on the
execution time. Here is the the time for compiling the corelib
Before: 8.61 secs (avg of 3 runs)
After: 8.74 secs (avg of 3 runs)
On the other hand, the size of the compacted region for the command
`#compact_tst 10` is smaller.
Before: 176687728
After: 153794704
The size before this change was 14.8% bigger.
For reference, using the old serializer we generate a buffer of size 105291117.
cc @kha
