The isc/platform.h header has been completely removed

The isc/platform.h header was left empty which things either already
moved to config.h or to appropriate headers.  This is just the final
cleanup commit.
70 jobs for !5162 with ondrej/remove-platform.h-header in 19 minutes and 11 seconds (queued for 7 seconds)
latest detached
Status Job ID Name Coverage
  Autoconf
passed #1847261
amd64 linux
autoreconf

00:00:18

 
  Precheck
passed #1847263
amd64 linux
clang-format

00:00:15

passed #1847264
amd64 linux
coccinelle

00:04:01

passed #1847265
amd64 linux
danger

00:00:16

passed #1847262
amd64 linux
misc

00:00:16

passed #1847266
amd64 linux
tarball-create

00:01:35

 
  Build
passed #1847279
amd64 linux
clang:asan

00:01:59

passed #1847282
amd64 linux
clang:buster:amd64

00:01:07

passed #1847285
amd64 libvirt
clang:freebsd12:amd64

00:01:22

passed #1847286
amd64 libvirt
clang:freebsd13:amd64

00:03:19

passed #1847287
amd64 libvirt
clang:openbsd:amd64

00:02:17

passed #1847281
amd64 linux
clang:tsan

00:01:14

passed #1847267
amd64 linux
gcc:alpine3.14:amd64

00:00:53

passed #1847278
amd64 linux
gcc:asan

00:01:36

passed #1847276
amd64 linux
gcc:bionic:amd64

00:00:56

passed #1847271
amd64 linux
gcc:buster:amd64

00:00:49

passed #1847268
amd64 linux
gcc:centos7:amd64

00:00:57

passed #1847269
amd64 linux
gcc:centos8:amd64

00:00:55

passed #1847277
amd64 linux
gcc:focal:amd64

00:01:01

passed #1847273
amd64 linux
gcc:out-of-tree

00:01:01

passed #1847272
amd64 linux
gcc:sid:amd64

00:01:10

passed #1847283
amd64 linux
gcc:softhsm2.4

00:00:48

passed #1847284
amd64 linux
gcc:softhsm2.6

00:01:01

passed #1847270
amd64 linux
gcc:stretch:amd64

00:01:04

passed #1847274
amd64 linux
gcc:tarball

00:01:03

passed #1847280
amd64 linux
gcc:tsan

00:01:08

passed #1847275
amd64 linux
gcc:tumbleweed:amd64

00:00:57

 
  Unit
passed #1847298
amd64 linux
unit:clang:asan

00:02:05

passed #1847301
amd64 linux
unit:clang:buster:amd64

00:01:26

passed #1847304
amd64 libvirt
unit:clang:freebsd12:amd64

00:01:58

passed #1847305
amd64 libvirt
unit:clang:freebsd13:amd64

00:03:32

passed #1847306
amd64 libvirt
unit:clang:openbsd:amd64

00:03:15

passed #1847300
amd64 linux
unit:clang:tsan

00:03:51

passed #1847288
amd64 linux
unit:gcc:alpine3.14:amd64

00:01:37

passed #1847297
amd64 linux
unit:gcc:asan

00:01:55

passed #1847295
amd64 linux
unit:gcc:bionic:amd64

00:01:23

passed #1847292
amd64 linux
unit:gcc:buster:amd64

00:02:27

passed #1847289
amd64 linux
unit:gcc:centos7:amd64

00:01:33

passed #1847290
amd64 linux
unit:gcc:centos8:amd64

00:01:27

passed #1847296
amd64 linux
unit:gcc:focal:amd64

00:01:29

passed #1847293
amd64 linux
unit:gcc:sid:amd64

00:01:23

passed #1847302
amd64 linux
unit:gcc:softhsm2.4

00:01:19

passed #1847303
amd64 linux
unit:gcc:softhsm2.6

00:01:43

passed #1847291
amd64 linux
unit:gcc:stretch:amd64

00:00:21

passed #1847299
amd64 linux
unit:gcc:tsan

00:04:26

passed #1847294
amd64 linux
unit:gcc:tumbleweed:amd64

00:01:24

 
  System
passed #1847317
amd64 linux
system:clang:asan

00:14:52

passed #1847320
amd64 linux
system:clang:buster:amd64

00:13:04

passed #1847323
amd64 libvirt
system:clang:freebsd12:amd64

00:11:46

passed #1847324
amd64 libvirt
system:clang:freebsd13:amd64

00:13:34

passed #1847319
amd64 linux
system:clang:tsan

00:17:26

passed #1847307
amd64 linux
system:gcc:alpine3.14:amd64

00:12:52

passed #1847316
amd64 linux
system:gcc:asan

00:14:57

passed #1847314
amd64 linux
system:gcc:bionic:amd64

00:12:11

passed #1847311
amd64 linux
system:gcc:buster:amd64

00:13:56

passed #1847308
amd64 linux
system:gcc:centos7:amd64

00:11:55

passed #1847309
amd64 linux
system:gcc:centos8:amd64

00:12:16

passed #1847315
amd64 linux
system:gcc:focal:amd64

00:12:54

passed #1847312
amd64 linux
system:gcc:sid:amd64

00:12:46

passed #1847321
amd64 linux
system:gcc:softhsm2.4

00:12:25

passed #1847322
amd64 linux
system:gcc:softhsm2.6

00:12:11

passed #1847310
amd64 linux
system:gcc:stretch:amd64

00:11:51

passed #1847318
amd64 linux
system:gcc:tsan

00:17:06

passed #1847313
amd64 linux
system:gcc:tumbleweed:amd64

00:11:54

 
  Docs
passed #1847325
amd64 linux
docs

00:00:55

 
  Postcheck
passed #1847329
amd64 linux
cppcheck

00:00:38

passed #1847326
amd64 linux
flake8

00:00:20

passed #1847330
amd64 linux
gcov

00:00:33

78.0%
passed #1847327
amd64 linux
pylint

00:00:30

passed #1847328
amd64 linux
scan-build

00:04:39