updated slice.ptr_rotate() to include a small rotation with buffer

[TheRadischen]

Change

Added a stack rotate for small rotations,
Buffer is set to [256]byte by default, but bigger would be better
Gries-Mill automatically exits when the rest fits in 256 bytes

Motivation

1. Small Slices are much faster to rotate with a buffer
2. Gries-Mills has a bad performance when one side is much smaller than the other side and so copying a small enough range outside the slice and shifting everything over by that amount mitigates the worst case for Gries-Mills.
   test: https://github.com/TheRadischen/odin-utils/tree/main/rotate

Benchmarks

average, type: int, many different rotation length
size: 10 iter: 10000 slice.rotate: 3┬Ás small_rotate: 1.1┬Ás diff: 2.727272727272727
size: 100 iter: 1000 slice.rotate: 12.2┬Ás small_rotate: 5.5┬Ás diff: 2.2181818181818183
size: 1000 iter: 100 slice.rotate: 52┬Ás small_rotate: 48.9┬Ás diff: 1.0633946830265848
size: 10000 iter: 10 slice.rotate: 489.4┬Ás small_rotate: 491.6┬Ás diff: 0.9955248169243287
size: 100000 iter: 5 slice.rotate: 4.9433ms small_rotate: 4.964ms diff: 0.9958299758259468
size: 1000000 iter: 5 slice.rotate: 105.5177ms small_rotate: 106.5284ms diff: 0.9905123891844804

worse case: type: int, small left rotation (0 to 32)
size: 10 iter: 100000 slice.rotate: 900ns small_rotate: 300ns diff: 3
size: 100 iter: 10000 slice.rotate: 3.7┬Ás small_rotate: 700ns diff: 5.285714285714286
size: 1000 iter: 1000 slice.rotate: 31.7┬Ás small_rotate: 2.4┬Ás diff: 13.208333333333334
size: 10000 iter: 100 slice.rotate: 309.3┬Ás small_rotate: 30.4┬Ás diff: 10.174342105263158
size: 100000 iter: 10 slice.rotate: 3.2229ms small_rotate: 362.1┬Ás diff: 8.900579950289975
size: 1000000 iter: 5 slice.rotate: 43.7188ms small_rotate: 22.3035ms diff: 1.9601766538884031

worste case: type: u8, small left rotation (0 to 100)
size: 10 iter: 10000 slice.rotate: 3.3┬Ás small_rotate: 1┬Ás diff: 3.3
size: 100 iter: 1000 slice.rotate: 12.5┬Ás small_rotate: 1.4┬Ás diff: 8.928571428571429
size: 1000 iter: 100 slice.rotate: 50.3┬Ás small_rotate: 2┬Ás diff: 25.15
size: 10000 iter: 10 slice.rotate: 409.2┬Ás small_rotate: 8.8┬Ás diff: 46.5
size: 100000 iter: 5 slice.rotate: 3.9645ms small_rotate: 123.6┬Ás diff: 32.0752427184466
size: 1000000 iter: 5 slice.rotate: 40.0785ms small_rotate: 1.6411ms diff: 24.42172932788983