Add symbols for FilteredRE2 and flags.

I discovered that we needed both because I broke a test that changes a
flag in the course of fixing a `make testinstall' failure.

Change-Id: I139ffc8cccddefa9812467de20a722c0e2303f9c
Reviewed-on: https://code-review.googlesource.com/2363
Reviewed-by: Paul Wankadia <junyer@google.com>
2 files changed