Fix undefined behavior in L1GtPatternWriter

[Dr15Jones]

PR description:

Bit shifting a negative number is undef. The starting number is now an unsigned value instead. This fixes a gcc 9 warning.

PR validation:

The warning is no longer present in gcc9 builds.
Using compiler explorer to test the change, the same value is returned for both gcc and clang after the change.
https://godbolt.org/z/oHP_EL

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-28291/12476

• This PR adds an extra 12KB to repository

• There are other open Pull requests which might conflict with changes you have proposed:

  • File L1Trigger/GlobalTriggerAnalyzer/src/L1GtPatternWriter.cc modified in PR(s): Fix gcc 9 warning in L1Trigger/GlobalTriggerAnalyzer #28277

[cmsbuild]

A new Pull Request was created by @Dr15Jones (Chris Jones) for master.

It involves the following packages:

L1Trigger/GlobalTriggerAnalyzer

@cmsbuild, @rekovic, @benkrikler can you please review it and eventually sign? Thanks.
@Martin-Grunewald this is something you requested to watch as well.
@davidlange6, @slava77, @fabiocos you are the release manager for this.

cms-bot commands are listed here

[Dr15Jones]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-run-pr-tests/3200/console Started: 2019/10/28 16:44

[cmsbuild]

+1
Tested at: dbe809e
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-46d42c/3200/summary.html

[cmsbuild]

Comparison job queued.

[Dr15Jones]

Solves same problem as #28277

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-46d42c/3200/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 34
• DQMHistoTests: Total histograms compared: 2961036
• DQMHistoTests: Total failures: 2
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2960693
• DQMHistoTests: Total skipped: 341
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 33 files compared)
• Checked 147 log files, 16 edm output root files, 34 DQM output files

[fabiocos]

@rekovic @benkrikler the change looks technical and straightforward, please have a look, I will integrate it after pre11 is built

[fabiocos]

+1

[fabiocos]

merge