use target_include_directories() instead of include_directories().
use target_include_directories() instead of include_directories().

Fixes #292.

Change-Id: If1cf4ad7836acd8d824a8b1e8de364a222a01e21
Reviewed-on: https://code-review.googlesource.com/c/re2/+/58150
Reviewed-by: Paul Wankadia <62d4e38bb1380f055ec4b899baa75e52af09c5f7@google.com>

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