Remove unused fields from EVP_PKEY.

None of these are ever set.

Change-Id: If92554a4c560bf8fa2d630c419a946711db30839
Reviewed-on: https://boringssl-review.googlesource.com/4114
Reviewed-by: Adam Langley <agl@google.com>

crypto/evp/evp.c

@@ -109,12 +109,6 @@ void EVP_PKEY_free(EVP_PKEY *pkey) {
   }
 
   free_it(pkey);
-  if (pkey->attributes) {
-    /* TODO(fork): layering: X509_ATTRIBUTE_free is an X.509 function. In
-     * practice this path isn't called but should be removed in the future. */
-    /*sk_X509_ATTRIBUTE_pop_free(pkey->attributes, X509_ATTRIBUTE_free);*/
-    assert(0);
-  }
   OPENSSL_free(pkey);
 }
 

include/openssl/evp.h

@@ -677,9 +677,6 @@ struct evp_pkey_st {
    * which element (if any) of the |pkey| union is valid. */
   int type;
 
-  /* TODO(fork): document */
-  int save_type;
-
   union {
     char *ptr;
     struct rsa_st *rsa; /* RSA */
@@ -688,16 +685,9 @@ struct evp_pkey_st {
     struct ec_key_st *ec; /* ECC */
   } pkey;
 
-  ENGINE *engine;
-
-  /* TODO(fork): document */
-  int save_parameters;
   /* ameth contains a pointer to a method table that contains many ASN.1
    * methods for the key type. */
   const EVP_PKEY_ASN1_METHOD *ameth;
-
-  /* TODO(fork): document; */
-  STACK_OF(X509_ATTRIBUTE) * attributes; /* [ 0 ] */
 } /* EVP_PKEY */;