Export `PCRE::no_more_args` and the functors.

To produce a DLL, CMake can automatically export code symbols,
but not data symbols, so we have to annotate those manually...

Set up CI to exercise `-D BUILD_SHARED_LIBS=ON` on everything.

Fixes #429.

Change-Id: Ibc232913e5f7121b9804748ea03422862893e482
Reviewed-on: https://code-review.googlesource.com/c/re2/+/61392
Reviewed-by: Paul Wankadia <junyer@google.com>
Reviewed-by: Perry Lorier <perryl@google.com>
3 files changed