Become partially -Wmissing-variable-declarations-clean.

There's a few things that will be kind of a nuisance and possibly not worth it
(crypto/asn1 dumps a lot of undeclared things, etc.). But it caught some
mistakes. Even without the warning, making sure to include the externs before
defining a function helps catch type mismatches.

Change-Id: I3dab282aaba6023e7cebc94ed7a767a5d7446b08
Reviewed-on: https://boringssl-review.googlesource.com/6484
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/ssl_cipher.c b/ssl/ssl_cipher.c
index e87835f..9365e6c 100644
--- a/ssl/ssl_cipher.c
+++ b/ssl/ssl_cipher.c
@@ -155,7 +155,7 @@
 
 
 /* kCiphers is an array of all supported ciphers, sorted by id. */
-const SSL_CIPHER kCiphers[] = {
+static const SSL_CIPHER kCiphers[] = {
     /* The RSA ciphers */
     /* Cipher 02 */
     {