external/boringssl: Sync to 5e578c9dba73460c3eb17f771c77fc8e36f7812e.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/58e449904e248f34bdfc2be7a609c58bcb0257b7..5e578c9dba73460c3eb17f771c77fc8e36f7812e

Test: BoringSSL CTS Presubmits
Change-Id: Ic1541b034545fa58a284ca35134b3719303455c7
diff --git a/src/include/openssl/conf.h b/src/include/openssl/conf.h
index b8ec12e..ae71575 100644
--- a/src/include/openssl/conf.h
+++ b/src/include/openssl/conf.h
@@ -89,6 +89,8 @@
   LHASH_OF(CONF_VALUE) *data;
 };
 
+DEFINE_STACK_OF(CONF_VALUE)
+
 
 /* NCONF_new returns a fresh, empty |CONF|, or NULL on error. The |method|
  * argument must be NULL. */