suggestion: Ways to specify `stack-size-threshold` for an item (function or module)

We already have awesome lint large_stack_frames with single cfg stack-size-threshold. But could be great to set the threshold for a function, or module, or maybe any scope if possible.

Example

I have stack limits:

• main-thread = 10240 bytes (10KiB, internally defined as 2560 32-bit units)
• audio-thread = 4096 bytes
• net-thread = 6144 bytes

It could be awesome to get some ability to set stack-limit by-hand for a function like this for example:

#[clippy::stack_size(threshold = 10240)]
fn main_task_root() {}

#[clippy::stack_size(threshold = 4096)]
fn sound_task_root() {}

Also could be great to differentiate it as "levels by threshold" like this:

#[clippy::stack_size(threshold = 10240, level = "deny")]
fn main_task_root() {}

#[clippy::stack_size(threshold = 4096, level = "deny")]   // total
#[clippy::stack_size(threshold = 4096/4, level = "warn")] // average max for "one of four" channel
fn sound_task_root() {}

And same for large_stack_arrays with array-size-threshold, because "what if I have two CPUs with various cache-lines on the board in-chain". Actually that is the case from my other project.

e.g.

• My main Cortex M7 have 32-byte cache-lines.
• Second CPU have an instruction cache with 16-byte lines.

#[clippy::array_size(threshold = 32)] // Main
fn main_task_root() {}

#[clippy::array_size(threshold = 16)] // Second
#[clippy::stack_size(threshold = 6144)]
fn net_task_root() {}

Start with the existing large_stack_frames and large_stack_arrays lints and determine how their global thresholds are configured. Define the supported scope and attribute syntax, including the proposed level behavior, then document and test the agreed semantics.