Make the fuzzer handle \p and \P specially.
Make the fuzzer handle \p and \P specially.

Change-Id: I7390d0474e4e9fd8cfb86be49f3a308b6e2ccde6
Reviewed-on: https://code-review.googlesource.com/c/38570
Reviewed-by: Paul Wankadia <62d4e38bb1380f055ec4b899baa75e52af09c5f7@google.com>

google/re2,google/re2,google/re2,google/re2,google/re2