Add additional tests for #18172 (Followup MR 3543)

There was still one active discussion [thread](ghc/ghc!3543 (comment 284325)) when MR !3543 got merged.

This MR adds the requested tests exercising the changes in
`compiler/GHC/HsToCore/Match/Literal.hs:warnAboutEmptyEnumerations` and its sub-functions.
23 jobs for !3653 with T18172_2 in 484 minutes and 14 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Lint
passed #409573
lint
ghc-linters

00:00:16

passed #409574
lint
lint-linters

00:00:15

passed #409577
lint
lint-submods

00:00:21

passed #409575
lint
lint-testsuite

00:00:16

passed #409576
lint
typecheck-testsuite

00:00:15

 
  Quick Build
passed #409578
x86_64-linux
hadrian-ghc-in-ghci

00:12:21

 
  Build
passed #409579
x86_64-linux
validate-x86_64-linux-deb9-hadrian

01:35:00

 
  Full Build
failed #409582
aarch64-linux allowed to fail
validate-aarch64-linux-deb9

02:57:18

failed #409583
armv7-linux allowed to fail
validate-armv7-linux-deb9

03:30:39

passed #409584
x86_64-linux
validate-i386-linux-deb9

01:34:57

passed #409581
x86_64-darwin
validate-x86_64-darwin

01:10:18

passed #409585
x86_64-linux
validate-x86_64-linux-deb9-debug

02:11:54

passed #409587
x86_64-linux
validate-x86_64-linux-deb9-dwarf

02:04:20

passed #409586
x86_64-linux
validate-x86_64-linux-deb9-integer-simple

01:28:43

passed #409580
x86_64-linux
validate-x86_64-linux-deb9-unreg-hadrian

03:25:23

passed #409675
x86_64-linux
validate-x86_64-linux-fedora27

00:40:46

failed #409590
new-x86_64-windows test allowed to fail
validate-x86_64-windows

00:31:21

failed #409589
new-x86_64-windows test allowed to fail
validate-x86_64-windows-hadrian

03:35:32

failed #409588
x86_64-linux
validate-x86_64-linux-fedora27

01:38:51

 
  Cleanup
passed #409591
x86_64-darwin
cleanup-darwin

00:00:21

 
  Packaging
failed #409592
x86_64-linux allowed to fail
doc-tarball

00:01:16

 
  Testing
manual #409593
x86_64-linux allowed to fail manual
hackage
passed #409594
x86_64-linux
perf-nofib

00:33:00

 
Name Stage Failure
failed
validate-aarch64-linux-deb9 Full Build
Uploading artifacts...
ghc-aarch64-linux-deb9.tar.xz: found 1 matching files and directories

junit.xml: found 1 matching files and directories

performance-metrics.tsv: found 1 matching files and directories

Uploading artifacts as "archive" to coordinator... ok
id=409582 responseStatus=201 Created token=4y1KDTgc
Uploading artifacts...
junit.xml: found 1 matching files and directories

Uploading artifacts as "junit" to coordinator... ok
id=409582 responseStatus=201 Created token=4y1KDTgc
ERROR: Job failed: exit code 1
failed
validate-armv7-linux-deb9 Full Build
Uploading artifacts...
ghc-armv7-linux-deb9.tar.xz: found 1 matching files

junit.xml: found 1 matching files

performance-metrics.tsv: found 1 matching files

Uploading artifacts to coordinator... ok
id=409583 responseStatus=201 Created token=wx7Dqkwo
Uploading artifacts...
junit.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=409583 responseStatus=201 Created token=wx7Dqkwo
ERROR: Job failed: exit code 1
failed
validate-x86_64-windows-hadrian Full Build
GO version:   go1.13.8
Built: 2020-06-19T21:12:23+0000
OS/Arch: windows/amd64
Uploading artifacts...
Runtime platform
arch=amd64 os=windows pid=5540 revision=6214287e version=13.1.0
junit.xml: found 1 matching files and directories

WARNING: Failed to load system CertPool: crypto/x509: system root pool is not available on Windows
Uploading artifacts as "junit" to coordinator... ok
id=409589 responseStatus=201 Created token=9H2UdJbM
ERROR: Job failed: exit status 1
failed
validate-x86_64-windows Full Build
Git branch:   13-1-stable
GO version: go1.13.8
Built: 2020-06-19T21:12:23+0000
OS/Arch: windows/amd64
Uploading artifacts...
Runtime platform
arch=amd64 os=windows pid=1236 revision=6214287e version=13.1.0
WARNING: junit.xml: no matching files
ERROR: No files to upload
ERROR: Job failed: exit status 1
failed
doc-tarball Packaging
Entering 'utils/haddock'
Entering 'utils/hsc2hs'
Downloading artifacts
Downloading artifacts for validate-x86_64-linux-deb9-debug (409585)...
Downloading artifacts from coordinator... ok
id=409585 responseStatus=200 OK token=k1yxC5BQ
Executing "step_script" stage of the job script
$ if [ ! -f "$LINUX_BINDIST" ]; then # collapsed multi-line command
Error: ghc-x86_64-mingw32.tar.xz does not exist. Did the 64-bit Windows job fail?
ERROR: Job failed: exit code 1