Kernel Panic when using Backspace

[bararchy]

When pressing the Backspace key for a long time and pressing "enter" a kernel panic is induced.

[SplittyDev]

Verified. This happens because of a bug with freeing.

In this case, Heap.free is called by Heap.realloc, which is used to increase the capacity of the String::Buffer used within Keyboard.gets.

This is temporarily fixed by increasing the buffer size in Keyboard.gets and removing the reallocation in String::Buffer.to_s. I will open a separate issue for the Heap bug.