Ensure that all the fixnum I/O functions are in the same order by type in the source.
Rename io-encdec functions.
Fix a memory leak when reading strings from FASL files.
Fix a memory leak of structure data fields.
Fix a leak of internal port data.
Correct a leak of FASL reader stream data.
Add a way to open a null input/output port from the VM.
Switch to the VM implementations of the input and output port predictes.
Switch to VM definitions for input and output port predicates.
Switch to a scheme definition of port-mode.
Update scc0.
Remove port-mode from the VM.
Switch to a scheme implementation of open null input and output port.
Remove the VM impls of open-null input and output port.
Restore the GC trigger based on malloc bytes.