Configure separate profiles for `cargo run --release` and `cargo flamegraph`

[CodeWenjiu]

My release profile contains numerous optimizations. To avoid conflicts, I’d like to use separate profiles for flamegraph generation and production builds. Is this feasible? Or is this a reasonable feature request?

[djc]

flamegraph is mostly passively maintainted -- I'd be open to looking at a PR in this direction. Are you aware that a bench profile already exists?