Add the simplest heap

[JalonWong]

It's very useful on a resource-constrained platform and avoids the need to use heapless modules. Its usage is the same as other heaps.
Because it's the simplest implementation, it doesn't free memory. Any memory you drop cannot be reused (it's leaked), so avoid dropping anything whenever possible.

[zeenix]

@JalonWong ?

[JalonWong]

@JalonWong ?

@zeenix Sorry, I will open the PR again when I fix CI errors.

[zeenix]

@JalonWong ?

@zeenix Sorry, I will open the PR again when I fix CI errors.

Thanks. Please also provide a bit of rationale/use case in the PR description and commit messages while you're at it. 🙏

[JalonWong]

@zeenix I have fixed all errors. But I'm not familiar with the permission of GitHub PR. Should I create a new one, or how can I reopen it?
I will add more descriptions later.

[zeenix]

But I'm not familiar with the permission of GitHub PR. Should I create a new one, or how can I reopen it?

I don't have permission to re-open either. I guess it's a bit too late. You shouldn't have closed the new PR. It was already there so we end up with every more noise. :( Anyway, please keep in mind in the future to do you best to reduce noise and number of PRs.

[zeenix]

I guess it's a bit too late.

I meant here that you'll need to create another PR (but let's not close that one 😉).