Unexpose the generic ex_data functions.

Callers are required to use the wrappers now. They still need OPENSSL_EXPORT
since crypto and ssl get built separately in the standalone shared library
build.

Change-Id: I61186964e6099b9b589c4cd45b8314dcb2210c89
Reviewed-on: https://boringssl-review.googlesource.com/4372
Reviewed-by: Adam Langley <agl@google.com>
11 files changed