tools: Add flamegraph subcommand

[djolertrk]

Implemented miden-debug flamegraph as a non-interactive execution mode. It drives DebugExecutor to completion one VM cycle at a time, samples callstack.frames() on each cycle, converts frames to semicolon-separated folded stack paths, aggregates cycle counts per stack, and renders the result as an SVG flame graph with inferno or as folded-stack text for external tools

It uses inferno crate as a new dependency.

[djolertrk]

Usage:

midenc \
    --emit masm,masp \
    --exe \
    --debug full \
    --entrypoint example_miden_project::entrypoint \
    target/wasm32-unknown-unknown/debug/example_miden_project.wasm


miden-debug flamegraph \
    --sysroot /path/to/compiler/target/debug/build/miden-core-lib-310dec8ab72220bd/out/assets \
    -o flamegraph.svg \
    example_miden_project.masp \
    -- 10
Executed 59920 cycles across 2 unique stack paths
Wrote flame graph to flamegraph.svg

[bitwalker]

Nice! It'd be useful, if you're able, to see an example like the one you show here, but generated from a run against one of the more involved example projects from the compiler repo, to get a sense of what a typical flamegraph would look like, just in case it raises any obvious issues in the process. That may require the transaction debugging stuff though, so we may have to wait until some of those other in-flight PRs and stuff land.

[greenhat]

Nice job!
Most of the code to be profiled will be the rollup code executed in transactions. It'd be great to find a way to expose the flamegraph generation API through the tx API. I think the most likely use case among the developers would be to enable flamegraph generation in their tests that are using the MockChain API.

[djolertrk]

Nice job! Most of the code to be profiled will be the rollup code executed in transactions. It'd be great to find a way to expose the flamegraph generation API through the tx API. I think the most likely use case among the developers would be to enable flamegraph generation in their tests that are using the MockChain API.

Yep. It does make sense.