std.ArrayList: add initBuffer to the unmanaged array list
This is useful when you want to have an array list backed by a fixed
slice of memory and no Allocator will be used.
It's an alternative to BoundedArray as you will see in the following
commit.
f6549a956dAndrew Kelley committed on 11/22/2023, 6:32:14 PMparentd5e21a4