std.fifo.LinearFifo: ensureUnusedCapacity and ensureTotalCapacity
std.fifo.LinearFifo: ensureUnusedCapacity and ensureTotalCapacity

Same as c8ae581fef6506a8234cdba1355ba7f0f449031a, but for LinearFifo.

andrewrk/zig,andrewrk/zig