build tensorflow with correct ppc64le_build_flags

[smuzaffar]

• Fix bootstrap to include gomp lib needed by rpm.
• Fix Tensorflow compilation flags for pcc64le

[smuzaffar]

please test

[cmsbuild]

A new Pull Request was created by @smuzaffar (Malik Shahzad Muzaffar) for branch IB/CMSSW_12_1_X/master.

@smuzaffar, @iarspider, @ddaina can you please review it and eventually sign? Thanks.
@perrotta, @dpiparo, @qliphy you are the release manager for this.
cms-bot commands are listed here

[smuzaffar]

please test for slc7_ppc64le_gcc9

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-5a1e49/19836/summary.html
COMMIT: 69a94fc
CMSSW: CMSSW_12_1_X_2021-10-21-2300/slc7_ppc64le_gcc9
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmsdist/7402/19836/install.sh to create a dev area with all the needed externals and cmssw changes.

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-5a1e49/19835/summary.html
COMMIT: 69a94fc
CMSSW: CMSSW_12_1_X_2021-10-21-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmsdist/7402/19835/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 5 differences found in the comparisons
• DQMHistoTests: Total files compared: 40
• DQMHistoTests: Total histograms compared: 2751113
• DQMHistoTests: Total failures: 11
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2751080
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 39 files compared)
• Checked 170 log files, 37 edm output root files, 40 DQM output files
• TriggerResults: no differences found

[smuzaffar]

+externals

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_12_1_X/master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)