This PR implements frame caching in the RemoteUnwinder class to significantly reduce memory reads when profiling remote processes with deep call stacks.
When cache_frames=True, the unwinder stores the frame chain from each sample and reuses unchanged portions in subsequent samples. Since most profiling samples capture similar call stacks (especially the parent frames), this optimization avoids repeatedly reading the same frame data from the target process.
The implementation adds a last_profiled_frame field to the thread state that tracks where the previous sample stopped. On the next sample, if the current frame chain reaches this marker, the cached frames from that point onward are reused instead of being re-read from remote memory.
The sampling profiler now enables frame caching by default.
Introduces LocationInfo struct sequence with end_lineno, col_offset, and
end_col_offset fields. Adds opcodes parameter to RemoteUnwinder that
extracts the currently executing opcode alongside its source span.
Refactors linetable parsing to correctly accumulate line numbers
separately from output values, fixing edge cases in computed_line.
