ldlibs: Try loading Clear Linux ld.so cache

Clear Linux patches glibc to put ld.so.cache in /var/cache/ldconfig/
to meet their goal of /etc being initially empty and reserved for the
sysadmin. We can handle this just like the conventional path: it
doesn't need to be architecture-specific.

Partially addresses
https://github.com/ValveSoftware/steam-runtime/issues/345

Signed-off-by: Simon McVittie <smcv@collabora.com>
6 jobs for master in 8 minutes and 17 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
manual #79685
allowed to fail manual
build:arch
passed #79681
build:asan

00:03:19

passed #79684
build:bionic

00:08:16

passed #79683
build:buster

00:08:03

passed #79682
build:stretch

00:08:09

passed #79680
build:ubsan

00:03:11