[mono-move] Fused jump and gas micro-ops

[calintat]

Description

Prototype gas instrumentation via fused jump instructions. Instead of inserting ChargeBlock ops between basic blocks, gas costs are stored directly in jump instructions (gas for unconditional jumps, gas_taken/gas_fallthrough for conditional jumps) and charged at dispatch time. Entry-block gas is stored in Function::entry_gas and charged in Interpreter::run. The instrumented program has the same instruction count as the original.

How Has This Been Tested?

Key Areas to Review

Type of Change

• New feature
• Bug fix
• Breaking change
• Performance improvement
• Refactoring
• Dependency update
• Documentation update
• Tests

Which Components or Systems Does This Change Impact?

• Validator Node
• Full Node (API, Indexer, etc.)
• Move/Aptos Virtual Machine
• Aptos Framework
• Aptos CLI/SDK
• Developer Infrastructure
• Move Compiler
• Other (specify)

Checklist

• I have read and followed the CONTRIBUTING doc
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I identified and added all stakeholders and component owners affected by this change as reviewers
• I tested both happy and unhappy path of the functionality
• I have made corresponding changes to the documentation