bug#51231: increase performance and usability of binary search with -P

[Carlo Arenas]

The following patch increase performance of grep when looking at
binary data, without any side effects:

Summary
  'cd grep; ./src/grep -Pc foo
/Users/carlo/Downloads/FreeBSD-13.0-BETA2-amd64.vhd' ran
    1.77 ± 0.02 times faster than 'cd grep.base; ./src/grep -Pc foo
/Users/carlo/Downloads/FreeBSD-13.0-BETA2-amd64.vhd'

Carlo

0001-pcre-only-match-UTF-8-if-needle-is-UTF-8-and-case-fo.patch
Description: Binary data