This callback is never used. The one caller I've ever seen is in Android
code which isn't built with BoringSSL and it was a no-op.
It also doesn't actually make much sense. A callback cannot reasonably
assume that it sees every, say, SSL_CTX created because the index may be
registered after the first SSL_CTX is created. Nor is there any point in
an EX_DATA consumer in one file knowing about an SSL_CTX created in
completely unrelated code.
Replace all the pointers with a typedef to int*. This will ensure code
which passes NULL or 0 continues to compile while breaking code which
passes an actual function.
This simplifies some object creation functions which now needn't worry
about CRYPTO_new_ex_data failing. (Also avoids bouncing on the lock, but
it's taking a read lock, so this doesn't really matter.)
BUG=391192
Change-Id: I02893883c6fa8693682075b7b130aa538a0a1437
Reviewed-on: https://boringssl-review.googlesource.com/6625
Reviewed-by: Adam Langley <agl@google.com>
8a58933db0