gcm_test.cc needs to access the internal GCM symbols. This is
unfortunate because it means that they have to be marked OPENSSL_EXPORT
just for this.
To compensate, modes.h is removed and its contents copied into
crypto/modes/internal.h.
Change-Id: I1777b2ef8afd154c43417137673a28598a7ec30e
Reviewed-on: https://boringssl-review.googlesource.com/6360
Reviewed-by: Adam Langley <alangley@gmail.com>
Initial fork from f2d678e6e89b6508147086610e985d4e8416e867 (1.0.2 beta).
(This change contains substantial changes from the original and
effectively starts a new history.)