gnu: Remove libcxxabi-6.

* gnu/packages/llvm.scm (libcxxabi-6): Delete variable.

Change-Id: I5bfad857a489d4dd513a15aaec52668a0eeb3d81

gnu: Remove libcxx+libcxxabi-6.

* gnu/packages/llvm.scm (libcxx+libcxxabi-6): Delete variable.

Change-Id: Ie1cdb96d1d2b303e8a7c30ee958315e8aa057810

gnu: Remove clang-toolchain-6.

* gnu/packages/llvm.scm (clang-toolchain-6): Delete variable.

Change-Id: I308e022ac72f9f66339af3356c3071955707f397

gnu: Remove fmt-6.

* gnu/packages/pretty-print.scm (fmt-6): Delete variable.

Change-Id: I17cb2e67878f13cbe9e8f40b671fa5010cd97974

gnu: Remove snappy-with-clang6.

* gnu/packages/compression.scm (snappy-with-clang6): Delete variable.

Change-Id: Ia3a3e534acf77ebf6edea3f2f9482c4e96ac1e38

gnu: Remove nanodbc-for-irods.

* gnu/packages/databases.scm (nanodbc-for-irods): Delete variable.

Change-Id: I7b6aecc3b21589e2a9b53974046c7a03e954c3fc

gnu: Remove boost-for-irods.

* gnu/packages/boost.scm (boost-for-irods): Delete variable.

Change-Id: I1bc02caa35a4eb8a49ce28348631e4fc69167579

gnu: Remove avro-cpp-1.9-for-irods.

* gnu/packages/serialization.scm (avro-cpp-1.9-for-irods): Delete variable.

Change-Id: Ic79e05769663fc3651fbf30ab32cef571dfe920d

gnu: Remove irods module.

* gnu/packages/irods.scm: Remove file.
* gnu/local.mk (GNU_SYSTEM_MODULES), po/packages/POTFILES.in:
Unregister file.

Fixes: guix/guix#1890
Change-Id: Ibf1120f67deea52950346cdcde39188ccbb6a696

gnu: Remove irods.

* gnu/packages/irods.scm (irods): Delete variable.

Change-Id: I81a0110ac51b18833493af8787137272f4a43c6a

gnu: Remove irods-client-icommands.

* gnu/packages/irods.scm (irods-client-icommands): Delete variable.

Change-Id: I0f3996d197a82bd4d7fd25d602277d01d65153dd

gnu: Remove heimdal.

* gnu/packages/kerberos.scm (heimdal): Delete variable.

Fixes: guix/guix#1886
Change-Id: I16a6031bc7ecc70d72e48f1656bbfe0b4453d06d

gnu: Remove krb5-auth-dialog.

* gnu/packages/gnome.scm (krb5-auth-dialog): Delete variable.

Fixes: guix/guix#1885
Change-Id: If9f9b49d2f99219564d628836d1c295ad236d518

gnu: Remove eigen-for-tensorflow.

* gnu/packages/algebra.scm (eigen-for-tensorflow): Delete variable.

Fixes: guix/guix#1856
Change-Id: Ia781c247c7a72b0da42506de15deee11e31972f1

gnu: Remove tensorflow.

* gnu/packages/machine-learning.scm (tensorflow): Delete variable.

Change-Id: I1db4876ebe71407e883b970342f5f1a13ef1d28d

gnu: Remove r-tfautograph.

* gnu/packages/cran.scm (r-tfautograph): Delete variable.

Change-Id: I22c67207eee71c9337ef6c7528b4aeebf30987ce

gnu: Remove r-tensorflow.

* gnu/packages/cran.scm (r-tensorflow): Delete variable.

Change-Id: I33bd19c27d4ae0326305c2ab1948e66bbcf0992b

gnu: Remove r-keras.

* gnu/packages/cran.scm (r-keras): Delete variable.

Change-Id: I6d78b52605795cb285f893043b6f733dbf93a3fb

gnu: Remove guile-aiscm.

* gnu/packages/machine-learning.scm (guile-aiscm): Delete variable.

Change-Id: I0f21c21aa4bc651a507d452099bc7cc603e3821d

gnu: Remove guile-aiscm-next.

* gnu/packages/machine-learning.scm (guile-aiscm-next): Delete variable.

Change-Id: I209c1efa45c938ef95241b7073f8154156d5d16d