Fix serialization errors when skipping compilation in FusionExecutor.

[rdspring1]

Serialization assumes that FusionExecutor always contains a compiled kernel. This PR updates serialization to skip compilation correctly.

[rdspring1]

!build

[rdspring1]

!build

[Priya2698]

General question: How does nvFuser handle if only one out of the many segments is not compiled? Do we skip serialization/deserialization for the entire fusion or is it segment-wise?

[rdspring1]

General question: How does nvFuser handle if only one out of the many segments is not compiled? Do we skip serialization/deserialization for the entire fusion or is it segment-wise?

We're skipping on a FusionExecutor basis, so it is segment-wise. Serialization follows the same behavior.

[Priya2698]

There are some new issues on my branch. I prefer either merging this to main or first fixing the issues in my branch so the root cause is clear. Wdyt?

[Priya2698]

!build

[rdspring1]

This PR can wait until the issues in your branch are fixed.

[Priya2698]

This PR can wait until the issues in your branch are fixed.

@rdspring1 We can merge this into my branch now. Could you resolve the conflicts, and finalize this PR? Thanks for the fix!

[rdspring1]

!build

[Priya2698]

LGTM. Added minor comments.