ISF_FatrasToolsG4: Flush G4cout/cerr streams in G4HadIntProcessor by-hand

Force flush Geant4 stream buffers to work around the problem discussed in ATLASSIM-5137. It seems to work locally but we should keep an eye on the ART tests to confirm.

cc: @jchapman @ssnyder

This merge request affects 1 package:

• Simulation/ISF/ISF_Fatras/ISF_FatrasToolsG4

This merge request affects 1 file:

• Simulation/ISF/ISF_Fatras/ISF_FatrasToolsG4/src/G4HadIntProcessor.cxx

Adding @jchapman ,@tcuhadar as watchers

added Simulation master review-pending-level-1 labels

CI Result FAILURE (hash 6493b3cc)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis	DetCommon
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
DetCommon: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 30102]

Jenkins please retry a build

This merge request affects 1 package:

• Simulation/ISF/ISF_Fatras/ISF_FatrasToolsG4

This merge request affects 1 file:

• Simulation/ISF/ISF_Fatras/ISF_FatrasToolsG4/src/G4HadIntProcessor.cxx

Adding @jchapman ,@tcuhadar as watchers

CI Result SUCCESS (hash 6493b3cc)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis	DetCommon
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 1
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
DetCommon: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 30116]

added bugfix label

"make" warning is clearly unrelated. Tests pass, changes look fine. L1 approving.

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit 46ef33b8

added sweep:ignore label