Remove native execution, grow heap as needed

[gavofyork]

This does two things:

• Removes non-encoded native execution;
• Grows the heap as needed up to some (very large) maximum as it runs out of memory.

This essentially avoids the memory requirement issue by assuming that runtimes are probably not going to try to run the node out of memory (a pre-existing assumption of native execution mode, so no worse than at present).

It may be reasonable to constrain the heap pages to a different maximum (i.e. not 3 GB) in the case of running untrusted (i.e. PVF) code.

It removes the direct native call execution. It currently keeps the indirect (encoded/decoded) native call execution.

TODO:

• Remove encoded native execution
• Different heap pages for PVF

Closes #7288

[xlc]

This closes #7288?

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.