see if BM and BMH need correction

[vityok]

Check if Boyer-Moore and Boyer-Moore-Horspool implementations need corrections outlined in: PR 724 for Microsoft STL (aka the Rytter correction).

some further info on HN.

Their implementation fails to find at all needle "aaa" in the haystack (actually located at offset 38):

        fbdhhihagdjcdibfdfdgbbhjcdifffdjdaighiaaaehigjegecjffcaecagcbiaeadhebggbijfdeihiceajbcjcjghhbjfcebge