n == length(str), p == length(pattern))
is utilized (with some tweaks for very short search patterns).
For natural language processing, however, this is not what
you probably want. It is because a bitwise match will
not give correct results in cases of:
Note that, the conversion of input data to Unicode is done as usual.
stri_count_fixed;
  stri_detect_fixed;
  stri_locate_all_fixed,
  stri_locate_first_fixed,
  stri_locate_first_fixed,
  stri_locate_last_fixed,
  stri_locate_last_fixed;
  stri_replace_all_fixed,
  stri_replace_first_fixed,
  stri_replace_first_fixed,
  stri_replace_last_fixed,
  stri_replace_last_fixed;
  stri_split_fixed;
  stringi-searchOther stringi_general_topics: stringi-arguments;
  stringi-encoding;
  stringi-locale;
  stringi-package;
  stringi-search-charclass;
  stringi-search-coll;
  stringi-search-regex;
  stringi-search