bench: Add test for function call overhead.

For a trivial operation, calling a function is 5 times slower than doing
operation inline.
bench: Add tests for constructing various containers from iterator.

Both "bound" (like, length known) and "unbound" (length unknown) are tested.
All of list, tuple, bytes, bytesarray offer approximately the same
performance, with "unbound" case being 30 times slower.
bench: Add test for map() vs inplace operations in array-likes.

map() is 5 times slower. That's mostly because of inefficiency of creating
containers from iterables of unknown length (like map()).
bench: Three ways to process a byte buffer.