Instrumented libraries: overhaul RPATH handling.

(1) Run separately for each package. Previously we ran it once as
a separate build step. This was the only way when all packages were installed in
the same directory, but since we now install each package in a temporary
directory first, it makes more sense to run there.
(2) Also fix the one remaining package which didn't use a temp directory.
(3) As a consequence of (1), fixed an issue caused by the fix_rpaths step
sometimes failing to run (
(4) Improve the DSO discovery regexp in Previously it only
covered DSOs which had unversioned symlinks pointing to them.
(5) Remove an outdated RPATH entry for dependent executables
(/usr/lib/x86_64-linux-gnu/ - we don't install anything there anymore).


Review URL:

Cr-Original-Commit-Position: refs/heads/master@{#304459}
Cr-Mirrored-Commit: 59a4c28d5e275836a5666f25bff4850215c7b481
3 files changed