Disable Thread Sanitizer in isc_dir_close()

There's a false positive reported by Thread Sanitizer between the
epoll_ctl() called from libuv and closedir() called from libisc.  The
Thread Sanitizer monitors file descriptors, but there's no possible way
the file descriptor in epoll_ctl() could be the same as the directory
being closed().  Let's just disable the the Thread Sanitizer for
isc_dir_close() function to prevent reporting of this false positive.

Closes: #2457

    WARNING: ThreadSanitizer: data race
      Write of size 8 at 0x000000000001 by thread T1:
	#0 closedir <null>
	#1 isc_dir_close lib/isc/unix/dir.c:134
	#2 dns_dnssec_findmatchingkeys lib/dns/dnssec.c:1526
	#3 statefile_exist lib/dns/zone.c:5858
	#4 dns_zone_secure_to_insecure lib/dns/zone.c:5905
	#5 dns_zone_use_kasp lib/dns/zone.c:5917
	#6 add_sigs lib/dns/zone.c:6901
	#7 dns__zone_updatesigs lib/dns/zone.c:8225
	#8 zone_nsec3chain lib/dns/zone.c:8921
	#9 zone_maintenance lib/dns/zone.c:11211
	#10 zone_timer lib/dns/zone.c:14674
	#11 dispatch lib/isc/task.c:1152
	#12 run lib/isc/task.c:1344
	#13 <null> <null>

      Previous read of size 8 at 0x000000000001 by thread T2:
	#0 epoll_ctl <null>
	#1 uv__platform_invalidate_fd <null>
	#2 uv_run <null>
	#3 <null> <null>

      Location is file descriptor 143 created by thread T2 at:
	#0 accept4 <null>
	#1 uv__accept <null>
	#2 <null> <null>

      Thread T1 (running) created by main thread at:
	#0 pthread_create <null>
	#1 isc_thread_create lib/isc/pthreads/thread.c:73
	#2 isc_taskmgr_create lib/isc/task.c:1434
	#3 create_managers bin/named/main.c:940
	#4 setup bin/named/main.c:1248
	#5 main bin/named/main.c:1548

      Thread T2 (running) created by main thread at:
	#0 pthread_create <null>
	#1 isc_thread_create lib/isc/pthreads/thread.c:73
	#2 isc_nm_start lib/isc/netmgr/netmgr.c:290
	#3 create_managers bin/named/main.c:934
	#4 setup bin/named/main.c:1248
	#5 main bin/named/main.c:1548

    SUMMARY: ThreadSanitizer: data race in closedir
76 jobs for !4713 with 2457-disable-thread-sanitizer-in-isc_dir_close in 38 minutes and 24 seconds (queued for 31 seconds)
detached
Status Job ID Name Coverage
  Autoconf
passed #1508877
amd64 linux
autoreconf

00:00:18

 
  Precheck
passed #1508881
amd64 linux
clang-format

00:00:22

passed #1508883
amd64 linux
coccinelle

00:03:45

passed #1508885
amd64 linux
danger

00:00:22

passed #1508879
amd64 linux
misc

00:00:23

passed #1508887
amd64 linux
tarball-create

00:01:31

 
  Build
passed #1508911
amd64 linux
clang:asan

00:02:18

passed #1508919
amd64 linux
clang:buster:amd64

00:00:51

passed #1508925
amd64 libvirt
clang:freebsd11:amd64

00:01:20

passed #1508926
amd64 libvirt
clang:freebsd12:amd64

00:01:29

passed #1508929
amd64 libvirt
clang:openbsd:amd64

00:02:23

passed #1508915
amd64 linux
clang:tsan

00:01:04

passed #1508889
amd64 linux
gcc:alpine3.12:amd64

00:00:49

passed #1508909
amd64 linux
gcc:asan

00:01:46

passed #1508897
amd64 linux
gcc:buster:amd64

00:00:41

passed #1508891
amd64 linux
gcc:centos7:amd64

00:00:48

passed #1508893
amd64 linux
gcc:centos8:amd64

00:00:49

passed #1508907
amd64 linux
gcc:focal:amd64

00:00:47

passed #1508917
amd64 linux
gcc:mutexatomics

00:00:46

passed #1508901
amd64 linux
gcc:out-of-tree

00:01:08

passed #1508899
amd64 linux
gcc:sid:amd64

00:00:59

passed #1508921
amd64 linux
gcc:softhsm2.4

00:00:47

passed #1508923
amd64 linux
gcc:softhsm2.6

00:00:49

passed #1508895
amd64 linux
gcc:stretch:amd64

00:00:56

passed #1508913
amd64 linux
gcc:tsan

00:01:07

passed #1508903
amd64 linux
gcc:tumbleweed:amd64

00:00:47

passed #1508905
amd64 linux
gcc:xenial:amd64

00:01:00

passed #1508931
amd64 windows
msvc:windows:amd64

00:00:53

 
  Unit
passed #1508953
amd64 linux
unit:clang:asan

00:01:46

passed #1508961
amd64 linux
unit:clang:buster:amd64

00:01:14

passed #1508966
amd64 libvirt
unit:clang:freebsd11:amd64

00:01:38

passed #1508968
amd64 libvirt
unit:clang:freebsd12:amd64

00:01:26

passed #1508971
amd64 libvirt
unit:clang:openbsd:amd64

00:03:29

passed #1508957
amd64 linux
unit:clang:tsan

00:03:16

passed #1509412
amd64 linux
unit:gcc:alpine3.12:amd64

00:01:12

passed #1508951
amd64 linux
unit:gcc:asan

00:01:41

passed #1508941
amd64 linux
unit:gcc:buster:amd64

00:02:24

passed #1508935
amd64 linux
unit:gcc:centos7:amd64

00:01:09

passed #1508937
amd64 linux
unit:gcc:centos8:amd64

00:01:05

passed #1508948
amd64 linux
unit:gcc:focal:amd64

00:01:16

passed #1508959
amd64 linux
unit:gcc:mutexatomics

00:01:06

passed #1508942
amd64 linux
unit:gcc:sid:amd64

00:01:12

passed #1508962
amd64 linux
unit:gcc:softhsm2.4

00:01:08

passed #1508965
amd64 linux
unit:gcc:softhsm2.6

00:01:06

passed #1508939
amd64 linux
unit:gcc:stretch:amd64

00:01:06

passed #1508955
amd64 linux
unit:gcc:tsan

00:04:05

passed #1509411
amd64 linux
unit:gcc:tumbleweed:amd64

00:01:03

passed #1508946
amd64 linux
unit:gcc:xenial:amd64

00:01:15

failed #1508933
amd64 linux
unit:gcc:alpine3.12:amd64

00:01:16

failed #1508944
amd64 linux
unit:gcc:tumbleweed:amd64

00:01:11

 
  System
passed #1508995
amd64 linux
system:clang:asan

00:14:24

passed #1509002
amd64 linux
system:clang:buster:amd64

00:13:07

passed #1509008
amd64 libvirt
system:clang:freebsd11:amd64

00:12:28

passed #1509413
libvirt amd64
system:clang:freebsd12:amd64

00:12:19

failed #1508999
amd64 linux allowed to fail
system:clang:tsan

00:17:09

passed #1508973
amd64 linux
system:gcc:alpine3.12:amd64

00:12:57

passed #1508993
amd64 linux
system:gcc:asan

00:15:09

passed #1508982
amd64 linux
system:gcc:buster:amd64

00:14:21

passed #1508975
amd64 linux
system:gcc:centos7:amd64

00:12:20

passed #1508977
amd64 linux
system:gcc:centos8:amd64

00:12:47

passed #1508991
amd64 linux
system:gcc:focal:amd64

00:13:07

passed #1509001
amd64 linux
system:gcc:mutexatomics

00:12:38

passed #1508984
amd64 linux
system:gcc:sid:amd64

00:12:20

passed #1509004
amd64 linux
system:gcc:softhsm2.4

00:13:12

passed #1509006
amd64 linux
system:gcc:softhsm2.6

00:12:17

passed #1508980
amd64 linux
system:gcc:stretch:amd64

00:11:41

failed #1508997
amd64 linux allowed to fail
system:gcc:tsan

00:17:14

passed #1508986
amd64 linux
system:gcc:tumbleweed:amd64

00:12:40

passed #1508989
amd64 linux
system:gcc:xenial:amd64

00:11:54

failed #1509010
amd64 libvirt
system:clang:freebsd12:amd64

00:12:34

 
  Docs
passed #1509012
amd64 linux
docs

00:00:49

 
  Postcheck
passed #1509017
amd64 linux
cppcheck

00:00:42

passed #1509014
amd64 linux
flake8

00:00:19

passed #1509018
amd64 linux
gcov

00:00:40

76.0%
passed #1509015
amd64 linux
pylint

00:00:22

passed #1509016
amd64 linux
scan-build

00:04:28

 
Name Stage Failure
failed
system:clang:tsan System
FAIL pipelined (exit status: 1)

$ find bin -name 'tsan.*' -exec python3 util/parse_tsan.py {} \;
Uploading artifacts for failed job
Uploading artifacts...
untracked: found 1744 files

Uploading artifacts as "archive" to coordinator... ok
id=1508999 responseStatus=201 Created token=v-4yFBS_
Cleaning up file based variables
ERROR: Job failed: exit code 1
failed
system:gcc:tsan System
FAIL pipelined (exit status: 1)

$ find bin -name 'tsan.*' -exec python3 util/parse_tsan.py {} \;
Uploading artifacts for failed job
Uploading artifacts...
untracked: found 1724 files

Uploading artifacts as "archive" to coordinator... ok
id=1508997 responseStatus=201 Created token=MXy7LMJR
Cleaning up file based variables
ERROR: Job failed: exit code 1