This update for go fixes the following issues:

Update to current stable go1.15 (bsc#1175132)

* Ensure 'Provides: golang(API) = %{api_version}' is consistent
to improve package resolution for common go dependency expressions
'BuildRequires: golang(API) >= 1.x' and BuildRequires: go >= 1.x
OBS projects that contain go code often have prjconf entries
'Prefer: go' which selects go metapackage over go1.x packages.
When go metapackage Provides: version is lower than go1.x versions,
'Prefer: go' is not effective and build failures occur with errors
unresolvable: have choice for golang(API) >= 1.13: go1.13 go1.14
Edits and changelog Jeff Kowalczyk (bsc#1172608)

* Unify '{version'} and '{short_version}' as '{api_version}' for
'Provides: golang(API) = %{api_version}'
* Use both 'BuildRequires: go%{api_version}' and 'Requires: go%{api_version}'
to trigger build errors if go1.x is unavailable
* Add aarch64 to supported systems for go-race via
%define tsan_arch x86_64 aarch64
* Add tsan_arch x86_64 aarch64 for suse_version >= 1500 and
sle_version >= 150000, formerly conditional on suse_version >= 1315
* Ensure %ifarch %{tsan_arch} always evaluates (nil does not work)
via dummy tsan_arch on systems where go-race is not supported

Update to current stable go1.14 (bsc#1164903)

* Remove redundant Provides: go-doc=%{version} per rpmlint warning

- Change suse_version >= 1315 (was 1550) defines short_version 1.12
go1.12 packages are available for SLE-12.

This update was imported from the SUSE:SLE-15:Update update project.