Explicitly instantiate matchee std::string in MatchesRegex
Explicitly instantiate matchee std::string in MatchesRegex

If this ever turns out to be a performance issue, we could use std::conditional and std::is_same to avoid copying std::strings.

Fixes #3949

PiperOrigin-RevId: 465353572
Change-Id: If2d691bccb626c692c87e006df5afe88a4ed1542

google/googletest,google/googletest,google/googletest,google/googletest