Fix build with opaque SSL_CTX and COMP_METHOD and do not redefine
DTLSv1.2 and TLSv1.3 related defined vailable in recent LibreSSL versions.

Index: lib_pypy/_cffi_ssl/_cffi_src/openssl/ssl.py
--- lib_pypy/_cffi_ssl/_cffi_src/openssl/ssl.py.orig
+++ lib_pypy/_cffi_ssl/_cffi_src/openssl/ssl.py
@@ -552,7 +552,7 @@ int SSL_CTX_set_max_early_data(SSL_CTX *, uint32_t);
 CUSTOMIZATIONS = """
 /* Added in 1.0.2 but we need it in all versions now due to the great
    opaquing. */
-#if CRYPTOGRAPHY_OPENSSL_LESS_THAN_102
+#if CRYPTOGRAPHY_OPENSSL_LESS_THAN_102 && !CRYPTOGRAPHY_IS_LIBRESSL
 /* from ssl/ssl_lib.c */
 const SSL_METHOD *SSL_CTX_get_ssl_method(SSL_CTX *ctx) {
     return ctx->method;
@@ -681,8 +681,8 @@ static const long Cryptography_HAS_SET_CERT_CB = 1;
 
 /* In OpenSSL 1.0.2i+ the handling of COMP_METHOD when OPENSSL_NO_COMP was
    changed and we no longer need to typedef void */
-#if (defined(OPENSSL_NO_COMP) && CRYPTOGRAPHY_OPENSSL_LESS_THAN_102I) || \
-    CRYPTOGRAPHY_IS_LIBRESSL
+#if (defined(OPENSSL_NO_COMP) && CRYPTOGRAPHY_OPENSSL_LESS_THAN_102I) && \
+    !CRYPTOGRAPHY_IS_LIBRESSL
 static const long Cryptography_HAS_COMPRESSION = 0;
 typedef void COMP_METHOD;
 #else
@@ -729,8 +729,6 @@ const SSL_METHOD *(*DTLS_client_method)(void) = NULL;
 static const long Cryptography_HAS_GENERIC_DTLS_METHOD = 1;
 #endif
 #if CRYPTOGRAPHY_OPENSSL_LESS_THAN_102
-static const long SSL_OP_NO_DTLSv1 = 0;
-static const long SSL_OP_NO_DTLSv1_2 = 0;
 long (*DTLS_set_link_mtu)(SSL *, long) = NULL;
 long (*DTLS_get_link_min_mtu)(SSL *) = NULL;
 #endif
@@ -836,7 +834,7 @@ static const long Cryptography_HAS_CIPHER_DETAILS = 0;
 static const long Cryptography_HAS_CIPHER_DETAILS = 1;
 #endif
 
-#if CRYPTOGRAPHY_OPENSSL_LESS_THAN_111
+#if CRYPTOGRAPHY_OPENSSL_LESS_THAN_111 && !CRYPTOGRAPHY_IS_LIBRESSL
 static const long Cryptography_HAS_TLSv1_3 = 0;
 static const long SSL_OP_NO_TLSv1_3 = 0;
 static const long SSL_VERIFY_POST_HANDSHAKE = 0;