Try to suppress warnings with FALLTHROUGH_INTENDED.
Try to suppress warnings with FALLTHROUGH_INTENDED.

Change-Id: I8694331547666c70873487c15d8bbac6cf88a75e
Reviewed-on: https://code-review.googlesource.com/24790
Reviewed-by: Paul Wankadia <62d4e38bb1380f055ec4b899baa75e52af09c5f7@google.com>

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