time C++ tests: Fix link error on CentOS 5

[Bruno Haible]

Building a gnulib testdir on CentOS 5, I get this link error:

g++  -Wno-error -g -O2  -L/home/bruno/inst-x86_64-64/lib -o test-time-c++ 
test-time-c++.o test-time-c++2.o libtests.a ../gllib/libgnu.a libtests.a 
../gllib/libgnu.a libtests.a    -lm -lm -lm -lm -lm -lm -lm -lm -lm -lm -lm
../gllib/libgnu.a(gettime.o): In function `gettime':
/home/bruno/testdir-all/build-64/gllib/../../gllib/gettime.c:32: undefined 
reference to `clock_gettime'
collect2: ld returned 1 exit status
make[4]: *** [test-time-c++] Error 1

This patch fixes it.


2022-09-17  Bruno Haible  <bruno@clisp.org>

        time C++ tests: Fix link error on CentOS 5.
        * modules/time-c++-tests (Makefile.am): Link test-time-c++ against
        $(LIB_CLOCK_GETTIME).

diff --git a/modules/time-c++-tests b/modules/time-c++-tests
index c811d6fd42..f8dd779965 100644
--- a/modules/time-c++-tests
+++ b/modules/time-c++-tests
@@ -16,5 +16,5 @@ if ANSICXX
 TESTS += test-time-c++
 check_PROGRAMS += test-time-c++
 test_time_c___SOURCES = test-time-c++.cc test-time-c++2.cc
-test_time_c___LDADD = $(LDADD) $(LIBINTL) $(LIB_NANOSLEEP)
+test_time_c___LDADD = $(LDADD) $(LIBINTL) $(LIB_NANOSLEEP) $(LIB_CLOCK_GETTIME)
 endif