Function scan_instruction_frame 

pub unsafe fn scan_instruction_frame(input: *mut u8) -> RawInstructionFrame

Parse just the instruction tail and account span from the loader input.

This supports both eager entrypoint parsing and lazy account iteration. The returned frame carries the original account span start so duplicate and canonical-account relationships remain defined at the loader level.

Safety

input must point to a valid Solana BPF input buffer.