Remove unused `#include`s from parser/cutils.c

Looks like these have been unused since
7c665f9c.
21 jobs for master in 119 minutes and 27 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Lint
passed #154357
lint
lint-linters

00:00:19

passed #154360
lint
lint-submods-branch

00:00:15

passed #154358
lint
lint-testsuite

00:00:16

passed #154359
lint
typecheck-testsuite

00:00:14

 
  Build
passed #154362
x86_64-linux
hadrian-ghc-in-ghci

00:18:09

passed #154364
x86_64-linux
release-x86_64-linux-deb9-dwarf

01:23:34

failed #154363
x86_64-linux
validate-x86_64-linux-deb9-debug

01:58:49

passed #154361
x86_64-linux
validate-x86_64-linux-deb9-hadrian

01:56:22

 
  Full Build
skipped #154366
aarch64-linux allowed to fail
validate-aarch64-linux-deb9
skipped #154367
x86_64-linux
validate-i386-linux-deb9
skipped #154365
x86_64-darwin
validate-x86_64-darwin
skipped #154368
x86_64-linux
validate-x86_64-linux-deb9-integer-simple
skipped #154369
x86_64-linux
validate-x86_64-linux-deb9-unreg
skipped #154370
x86_64-linux
validate-x86_64-linux-fedora27
skipped #154372
x86_64-windows allowed to fail
validate-x86_64-windows
skipped #154371
x86_64-windows allowed to fail
validate-x86_64-windows-hadrian
 
  Cleanup
passed #154373
x86_64-darwin
cleanup-darwin

00:00:05

 
  Packaging
skipped #154374
x86_64-linux allowed to fail
doc-tarball
 
  Testing
skipped #154375
x86_64-linux allowed to fail manual
hackage
skipped #154376
x86_64-linux
perf-nofib
 
  Deploy
skipped #154377
x86_64-linux allowed to fail
pages
 
Name Stage Failure
failed
validate-x86_64-linux-deb9-debug Build
$ cp -Rf $HOME/.cabal cabal-cache
Uploading artifacts...
ghc-*.tar.xz: found 1 matching files
junit.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=154363 responseStatus=201 Created token=tHzYtd_Y
Uploading artifacts...
junit.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=154363 responseStatus=201 Created token=tHzYtd_Y
ERROR: Job failed: exit code 1