guix: consolidate glibc 2.27 package

Refactor our glibc 2.27 to be a single 'package', and avoid the use of
`package-with-extra-configure-variable`. This also lets us drop the
`enable_werror` workaround, and just use --disable-werror directly.

Employ the same workaround as the Guix glibc, to avoid a "permission
denied" failure during build:
```bash
make  subdir=sunrpc -C sunrpc ..=../ subdir_install
make[2]: Entering directory '/tmp/guix-build-glibc-cross-x86_64-linux-gnu-2.27.drv-0/source/sunrpc'
.././scripts/mkinstalldirs /gnu/store/ga8jciqrd5lh52m572x3mk4q1smf5agq-glibc-cross-x86_64-linux-gnu-2.27/include/rpc
mkdir -p -- /gnu/store/ga8jciqrd5lh52m572x3mk4q1smf5agq-glibc-cross-x86_64-linux-gnu-2.27/include/rpc
/gnu/store/kvpvk5wh70wdbjnr83hh85rg22ysxm9h-coreutils-8.32/bin/install -c -m 644 rpc/netdb.h /gnu/store/ga8jciqrd5lh52m572x3mk4q1smf5agq-glibc-cross-x86_64-linux-gnu-2.27/include/rpc/netdb.h
.././scripts/mkinstalldirs /gnu/store/ga8jciqrd5lh52m572x3mk4q1smf5agq-glibc-cross-x86_64-linux-gnu-2.27/include/nfs
mkdir -p -- /gnu/store/ga8jciqrd5lh52m572x3mk4q1smf5agq-glibc-cross-x86_64-linux-gnu-2.27/include/nfs
/gnu/store/kvpvk5wh70wdbjnr83hh85rg22ysxm9h-coreutils-8.32/bin/install -c -m 644 ../sysdeps/unix/sysv/linux/nfs/nfs.h /gnu/store/ga8jciqrd5lh52m572x3mk4q1smf5agq-glibc-cross-x86_64-linux-gnu-2.27/include/nfs/nfs.h
/gnu/store/kvpvk5wh70wdbjnr83hh85rg22ysxm9h-coreutils-8.32/bin/install -c -m 644 /tmp/guix-build-glibc-cross-x86_64-linux-gnu-2.27.drv-0/build/gnu/lib-names-64.h /gnu/store/ga8jciqrd5lh52m572x3mk4q1smf5agq-glibc-cross-x86_64-linux-gnu-2.27/include/gnu/lib-names-64.h
/gnu/store/kvpvk5wh70wdbjnr83hh85rg22ysxm9h-coreutils-8.32/bin/install -c -m 644 etc.rpc /etc/rpc
/gnu/store/kvpvk5wh70wdbjnr83hh85rg22ysxm9h-coreutils-8.32/bin/install: cannot create regular file '/etc/rpc': Permission denied
make[2]: *** [Makefile:197: /etc/rpc] Error 1
```

0 files changed, 0 insertions, 0 deletions