Add C++ declarations to dns/fixedname.h

(cherry picked from commit 94a1c853)
14 jobs for cplusplusize_dns_fixedname_h-v9_12 in 8 minutes and 36 seconds (queued for 7 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #54584
amd64 docker linux

00:00:18

 
  Build
passed build:centos:centos6:amd64 #54585
amd64 docker linux

00:02:40

passed build:centos:centos7:amd64 #54586
amd64 docker linux

00:02:50

passed build:debian:sid:amd64 #54587
amd64 docker linux

00:03:12

passed build:debian:sid:i386 #54588
i386 docker linux

00:03:26

 
  Test
passed install:debian:sid:amd64 #54597
amd64 docker linux

00:01:27

passed systemtest:centos:centos6:amd64 #54593
amd64 docker linux

00:04:45

passed systemtest:centos:centos7:amd64 #54594
amd64 docker linux

00:04:36

passed systemtest:debian:sid:amd64 #54595
amd64 docker linux

00:04:41

passed systemtest:debian:sid:i386 #54596
i386 docker linux

00:04:48

passed unittest:centos:centos6:amd64 #54589
amd64 docker linux

00:00:56

passed unittest:centos:centos7:amd64 #54590
amd64 docker linux

00:00:51

passed unittest:debian:sid:amd64 #54591
amd64 docker linux

00:00:52

passed unittest:debian:sid:i386 #54592
i386 docker linux

00:00:47