Use dlsym for -ldl detection

-fsanitize=thread hijacks dlopen() and dlclose(), therefore dlopen()
won't request -ldl to be used for linking during Autoconf test. Check
for dlsym() presence will fail and dlzexternal and dyndb system tests
won't run.

Retrieved from 2dd54fa6.
89 jobs for !4575 with mnowak/fsanitize-thread-hijacks-dlopen-and-dlclose-use-dlsym in 1 minute and 36 seconds (queued for 8 seconds)
detached
Status Job ID Name Coverage
  Precheck
passed #1413838
linux amd64
autoreconf

00:00:23

passed #1413840
linux amd64
clang-format

00:00:16

passed #1413841
linux amd64
coccinelle

00:01:11

passed #1413842
linux amd64
danger

00:00:23

passed #1413839
linux amd64
misc

00:00:21

 
  Build
canceled #1413857
linux amd64
clang:asan

00:01:03

canceled #1413864
linux amd64
clang:buster:amd64

00:01:03

canceled #1413866
amd64 libvirt
clang:freebsd11:amd64

00:00:58

canceled #1413867
amd64 libvirt
clang:freebsd12:amd64

00:00:58

canceled #1413868
amd64 libvirt
clang:openbsd:amd64

00:00:57

canceled #1413859
linux amd64
clang:tsan

00:01:08

canceled #1413861
linux amd64
clang:tsan:noatomics

00:01:08

canceled #1413843
linux amd64
gcc:alpine3.12:amd64

00:01:08

canceled #1413856
linux amd64
gcc:asan

00:01:04

canceled #1413849
linux amd64
gcc:buster:amd64

00:01:08

canceled #1413845
linux amd64
gcc:centos6:amd64

00:01:03

canceled #1413844
linux i386
gcc:centos6:i386

00:01:08

canceled #1413846
linux amd64
gcc:centos7:amd64

00:01:08

canceled #1413847
linux amd64
gcc:centos8:amd64

00:01:08

canceled #1413853
linux amd64
gcc:fedora33:amd64

00:01:05

canceled #1413855
linux amd64
gcc:focal:amd64

00:01:04

canceled #1413862
linux amd64
gcc:mutexatomics

00:01:07

canceled #1413863
linux amd64
gcc:noatomics

00:01:03

canceled #1413851
linux amd64
gcc:out-of-tree

00:01:07

canceled #1413865
linux amd64
gcc:pkcs11

00:01:02

canceled #1413850
linux amd64
gcc:sid:amd64

00:01:07

canceled #1413848
linux amd64
gcc:stretch:amd64

00:01:08

canceled #1413858
linux amd64
gcc:tsan

00:01:08

canceled #1413860
linux amd64
gcc:tsan:noatomics

00:01:08

canceled #1413852
linux amd64
gcc:tumbleweed:amd64

00:01:06

canceled #1413854
linux amd64
gcc:xenial:amd64

00:01:05

passed #1413870
amd64 windows
msvc:windows:amd64

00:01:12

canceled #1413869
linux amd64
nolibtool:sid:amd64

00:01:00

 
  Unit
canceled #1413884
linux amd64
unit:clang:asan

canceled #1413891
linux amd64
unit:clang:buster:amd64

canceled #1413893
amd64 libvirt
unit:clang:freebsd11:amd64

canceled #1413894
amd64 libvirt
unit:clang:freebsd12:amd64

canceled #1413886
linux amd64
unit:clang:tsan

canceled #1413888
linux amd64
unit:clang:tsan:noatomics

canceled #1413871
linux amd64
unit:gcc:alpine3.12:amd64

canceled #1413883
linux amd64
unit:gcc:asan

canceled #1413877
linux amd64
unit:gcc:buster:amd64

canceled #1413873
linux amd64
unit:gcc:centos6:amd64

canceled #1413872
linux i386
unit:gcc:centos6:i386

canceled #1413874
linux amd64
unit:gcc:centos7:amd64

canceled #1413875
linux amd64
unit:gcc:centos8:amd64

canceled #1413880
linux amd64
unit:gcc:fedora33:amd64

canceled #1413882
linux amd64
unit:gcc:focal:amd64

canceled #1413889
linux amd64
unit:gcc:mutexatomics

canceled #1413890
linux amd64
unit:gcc:noatomics

canceled #1413892
linux amd64
unit:gcc:pkcs11

canceled #1413878
linux amd64
unit:gcc:sid:amd64

canceled #1413876
linux amd64
unit:gcc:stretch:amd64

canceled #1413885
linux amd64
unit:gcc:tsan

canceled #1413887
linux amd64
unit:gcc:tsan:noatomics

canceled #1413879
linux amd64
unit:gcc:tumbleweed:amd64

canceled #1413881
linux amd64
unit:gcc:xenial:amd64

canceled #1413895
linux amd64
unit:nolibtool:sid:amd64

 
  System
canceled #1413909
linux amd64
system:clang:asan

canceled #1413916
linux amd64
system:clang:buster:amd64

canceled #1413918
amd64 libvirt
system:clang:freebsd11:amd64

canceled #1413919
amd64 libvirt
system:clang:freebsd12:amd64

canceled #1413911
linux amd64 allowed to fail
system:clang:tsan

canceled #1413913
linux amd64 allowed to fail
system:clang:tsan:noatomics

canceled #1413896
linux amd64
system:gcc:alpine3.12:amd64

canceled #1413908
linux amd64
system:gcc:asan

canceled #1413902
linux amd64
system:gcc:buster:amd64

canceled #1413898
linux amd64
system:gcc:centos6:amd64

canceled #1413897
linux i386
system:gcc:centos6:i386

canceled #1413899
linux amd64
system:gcc:centos7:amd64

canceled #1413900
linux amd64
system:gcc:centos8:amd64

canceled #1413905
linux amd64
system:gcc:fedora33:amd64

canceled #1413907
linux amd64
system:gcc:focal:amd64

canceled #1413914
linux amd64
system:gcc:mutexatomics

canceled #1413915
linux amd64
system:gcc:noatomics

canceled #1413917
linux amd64
system:gcc:pkcs11

canceled #1413903
linux amd64
system:gcc:sid:amd64

canceled #1413901
linux amd64
system:gcc:stretch:amd64

canceled #1413910
linux amd64 allowed to fail
system:gcc:tsan

canceled #1413912
linux amd64 allowed to fail
system:gcc:tsan:noatomics

canceled #1413904
linux amd64
system:gcc:tumbleweed:amd64

canceled #1413906
linux amd64
system:gcc:xenial:amd64

canceled #1413920
linux amd64
system:nolibtool:sid:amd64

 
  Docs
passed #1413921
linux amd64
docs

00:00:50

 
  Postcheck
passed #1413925
linux amd64
cppcheck

00:00:43

passed #1413922
linux amd64
flake8

00:00:47

canceled #1413926
linux amd64
gcov

passed #1413923
linux amd64
pylint

00:00:44

canceled #1413924
linux amd64
scan-build

00:00:56