Port Gnulib test fixes from upstream

gnutls-3.6.15-gnulib-perror-tests.patch

@@ -0,0 +1,46 @@
+From 175e0bc72808d564074c4adcc72aeadb74adfcc6 Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Thu, 27 Aug 2020 17:52:58 -0700
+Subject: [PATCH] perror, strerror_r: remove unportable tests
+
+Problem reported by Florian Weimer in:
+https://lists.gnu.org/r/bug-gnulib/2020-08/msg00220.html
+* tests/test-perror2.c (main):
+* tests/test-strerror_r.c (main): Omit unportable tests.
+---
+ ChangeLog               | 8 ++++++++
+ tests/test-perror2.c    | 3 ---
+ tests/test-strerror_r.c | 3 ---
+ 3 files changed, 8 insertions(+), 6 deletions(-)
+
+diff --git a/gl/tests/test-perror2.c b/gl/tests/test-perror2.c
+index 1d14eda7b..c6214dd25 100644
+--- a/gl/tests/test-perror2.c
++++ b/gl/tests/test-perror2.c
+@@ -79,9 +79,6 @@ main (void)
+     errno = -5;
+     perror ("");
+     ASSERT (!ferror (stderr));
+-    ASSERT (msg1 == msg2 || msg1 == msg4 || STREQ (msg1, str1));
+-    ASSERT (msg2 == msg4 || STREQ (msg2, str2));
+-    ASSERT (msg3 == msg4 || STREQ (msg3, str3));
+     ASSERT (STREQ (msg4, str4));
+ 
+     free (str1);
+diff --git a/gl/tests/test-strerror_r.c b/gl/tests/test-strerror_r.c
+index b11d6fd9f..c1dbcf837 100644
+--- a/gl/tests/test-strerror_r.c
++++ b/gl/tests/test-strerror_r.c
+@@ -165,9 +165,6 @@ main (void)
+ 
+     strerror_r (EACCES, buf, sizeof buf);
+     strerror_r (-5, buf, sizeof buf);
+-    ASSERT (msg1 == msg2 || msg1 == msg4 || STREQ (msg1, str1));
+-    ASSERT (msg2 == msg4 || STREQ (msg2, str2));
+-    ASSERT (msg3 == msg4 || STREQ (msg3, str3));
+     ASSERT (STREQ (msg4, str4));
+ 
+     free (str1);
+-- 
+2.26.2
+

gnutls.spec

@@ -3,6 +3,7 @@ Version:	3.6.15
 Release: 1%{?dist}
 Patch1:	gnutls-3.6.7-no-now-guile.patch
 Patch2:	gnutls-3.2.7-rpath.patch
+Patch3:	gnutls-3.6.15-gnulib-perror-tests.patch
 %bcond_without dane
 %if 0%{?rhel}
 %bcond_with guile