external/boringssl: Sync to 3a18bf04745c0ef9850efeec1a52e402c4392388.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/9a127b43b8b78a135d6b64a3e25b8a704c2c069f..3a18bf04745c0ef9850efeec1a52e402c4392388

Test: BoringSSL CTS Presubmits.
Change-Id: Id39a146b1a6d7483f4142a7c191796ba65f32883
76 files changed