Since Bazel doesn't have a shared vs static concept that's exposed to
the build rules (as far as I know) symbol visibility would mean that the
symbols might be exposed when building a larger library. That could be
fixed with a linker script, but this change appears to be slightly more
useful for our consumers.
(Also, if we're going to set -fvisibility=hidden, we should also have set
the defines needed to include the visibility annotations.)
Change-Id: Ic7d64a553da48cfb9cf5460d26254de7e105fd65
Reviewed-on: https://boringssl-review.googlesource.com/8664
Reviewed-by: Adam Langley <agl@google.com>
abe22b605f