BUG #17304: Test failure with -fsanitize=undefined

The following bug has been logged on the website:

Bug reference:      17304
Logged by:          Martin Liška
Email address:      marxin.liska@gmail.com
PostgreSQL version: 14.1
Operating system:   Linux
Description:

F="-fsanitize=undefined -g -O2" && export CFLAGS="$F" && export
CXXFLAGS="$F" && export LDFLAGS="$F" && ./configure
...
make check
...

cat /home/marxin/Programming/postgres/src/test/regress/regression.diffs
diff -U3
/home/marxin/Programming/postgres/src/test/regress/expected/errors.out
/home/marxin/Programming/postgres/src/test/regress/results/errors.out
---
/home/marxin/Programming/postgres/src/test/regress/expected/errors.out    2021-08-16
18:20:32.157439777 +0200
+++
/home/marxin/Programming/postgres/src/test/regress/results/errors.out    2021-11-30
15:05:59.927802757 +0100
@@ -17,6 +17,7 @@
 -- SELECT
 -- this used to be a syntax error, but now we allow an empty target list
 select;
+print.c:969:4: runtime error: null pointer passed as argument 1, which is
declared to never be null
 --
 (1 row)
 
diff -U3
/home/marxin/Programming/postgres/src/test/regress/expected/union.out
/home/marxin/Programming/postgres/src/test/regress/results/union.out
---
/home/marxin/Programming/postgres/src/test/regress/expected/union.out    2021-11-11
15:59:29.507314173 +0100
+++
/home/marxin/Programming/postgres/src/test/regress/results/union.out    2021-11-30
15:06:00.667797080 +0100
@@ -936,6 +936,7 @@
 -- Check behavior with empty select list (allowed since 9.4)
 --
 select union select;
+print.c:969:4: runtime error: null pointer passed as argument 1, which is
declared to never be null
 --
 (1 row)
 
diff -U3
/home/marxin/Programming/postgres/src/test/regress/expected/alter_table.out
/home/marxin/Programming/postgres/src/test/regress/results/alter_table.out
---
/home/marxin/Programming/postgres/src/test/regress/expected/alter_table.out    2021-11-11
15:59:29.495314262 +0100
+++
/home/marxin/Programming/postgres/src/test/regress/results/alter_table.out    2021-11-30
15:06:06.555751926 +0100
@@ -1530,6 +1530,7 @@
 alter table atacc1 drop d;
 alter table atacc1 drop b;
 select * from atacc1;
+print.c:969:4: runtime error: null pointer passed as argument 1, which is
declared to never be null
 --
 (1 row)