Reduce public visibility of compute-budget APIs

[pgarg66]

Problem

APIs and structs in compute-budget crate can have reduced visibility.

Summary of Changes

Update the visibility using feature config.

Fixes #

[pgarg66]

Hey @kevinheavey, 5e669b4 should address your comments in #4606.

[t-nelson]

isn't compute budget a protocol implementation detail used to configure the svm, not actually part of the svm?

[kevinheavey]

Could we leave these fields pub please? LiteSVM lets people overwrite the ComputeBudget fields.

I'm open to being told these fields are quite unstable and we should limit to a subset, since I doubt many users care about overwriting poseidon_cost_coefficient_a etc

[pgarg66]

isn't compute budget a protocol implementation detail used to configure the svm, not actually part of the svm?

Ideally yes. In present form, the most of the fields are only used internally by SVM, with hardcoded values set in the constructors (default(), from() and new()):

agave/compute-budget/src/compute_budget.rs

Line 134 in fa62025

impl Default for ComputeBudget {

Maybe we should allow the user of SVM to tweak these values, even though in Agave we are not changing most of it.

@t-nelson does that align with your thoughts?