Add SSL_get_tlsext_status_type() method

The tlsext_status_type field in SSL is used by e.g. OpenResty to determine
if the client requested the certificate status, but SSL is now opaque.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c
index de7f1c0..025c003 100644
--- a/ssl/s3_lib.c
+++ b/ssl/s3_lib.c
@@ -2971,6 +2971,11 @@
         ret = 1;
         break;
 
+    case SSL_CTRL_GET_TLSEXT_STATUS_REQ_TYPE:
+        *(int *)parg = s->tlsext_status_type;
+        ret = 1;
+        break;
+
     case SSL_CTRL_SET_TLSEXT_STATUS_REQ_TYPE:
         s->tlsext_status_type = larg;
         ret = 1;