This update for gcc7 to 7.3 contains a number of fixes and improvements.

The following features were added:

Mitigations for Spectre Variant 2:
- retpoline support via -mindirect-branch=, -mfunction-return= and friends was added which
can be used to mitigate Spectre Variant 2.2.

This feature was implemented for x86 (bnc#1074621) and also for the IBM Z platform (bnc#1083946).

The following issues were fixed:

- nvptx offload target compiler install issues
- newlib parts split into cross-nvptx-newlib7-devel
- Chromium build failures (bnc#1083290)