RM: gcc-4.8: no longer used

[Steve Langasek]

With the latest round of removals for Ubuntu Touch-related packages from bionic, gcc-4.8 no longer has any non-alternative reverse-depends.

$ liblist='lib(x32|32|64|sf)?(gomp1|quadmath0|atomic1|itm1|objc4|stdc\+\+6|gfortran3|tsan0)'
$ rmadison -s bionic -S gcc-4.8 | grep -E "\b$liblist[[:space:]]"
$ reverse-depends src:gcc-4.8 | grep -vE "\b$liblist\)"
Reverse-Depends
===============
* gcc-4.8-doc (for gcc-4.8-base)
* libboost1.62-dev (for libstdc++-4.8-dev)
* libboost1.65-dev (for libstdc++-4.8-dev)
* nvidia-cuda-toolkit [amd64 ppc64el] (for gcc-4.8)
* nvidia-cuda-toolkit [amd64 ppc64el] (for g++-4.8)

Packages without architectures listed are reverse-dependencies in: amd64, arm64, armhf, i386, ppc64el, s390x
$

We should drop it from the archive for 18.04.

[Steve Langasek (vorlon)]

Removed 2019-02-21:

(From Debian) ROM; obsolete GCC version; Debian bug #821336