Don't mention test failures on Ubuntu 16.04 in PROBLEMS

Ubuntu 16.04 LTS reached end of life on April 30th, 2021.
Furthermore, test failures don't seem significant enough to warrant an
entry.  It's rather cosmetic.
* etc/PROBLEMS: Delete entry on test failures on Ubuntu 16.04.

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 781a54c06bde44f19e4e04531ba41100c588fb86..c72322811bc36e3a24ad136a3db4c591c7fc3480 100644 (file)
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -3546,15 +3546,6 @@ as a macro.  If the definition (in both unex*.c and malloc.c) is wrong,
 it can cause problems like this.  You might be able to find the correct
 value in the man page for a.out(5).
 
-* 'make check' failures
-
-** emacs-module-tests fail on Ubuntu 16.04
-
-This is due to a bug in GCC that was fixed in 2015; see
-<https://lists.gnu.org/r/emacs-devel/2018-09/msg00548.html>.
-You can work around the problem by using a later version of GCC or of
-Ubuntu, or by configuring without modules.
-
 * Problems on legacy systems
 
 This section covers bugs reported on very old hardware or software.