Auto merge of #150 - andjo403:repeat, r=Amanieu
Auto merge of #150 - andjo403:repeat, r=Amanieu

micro optimize repeat function

makes it easier for the compiler and the reader with less code :)

for "prof" https://godbolt.org/z/5bdD2b
when I tried cargo bench I got very large variance between runs was multiple test that one time had 2x improvement to the next time have a minor regression so have more trust in the llvm-mca result.

rust-lang/hashbrown,rust-lang/hashbrown