test: GCC 4.7 expects the definition of value_diff up front
test: GCC 4.7 expects the definition of value_diff up front

It won't look lower in the file. However I think that is expected
operation for all compilers. How did this work previously?

oleg-alexandrov/StereoPipeline,NeoGeographyToolkit/StereoPipeline,ScottMcMichael/StereoPipeline,njwilson23/StereoPipeline,oleg-alexandrov/StereoPipeline,njwilson23/StereoPipeline,njwilson23/StereoPipeline,ScottMcMichael/StereoPipeline,DougFirErickson/StereoPipeline,NeoGeographyToolkit/StereoPipeline,NeoGeographyToolkit/StereoPipeline,aaronknister/StereoPipeline,DougFirErickson/StereoPipeline,DougFirErickson/StereoPipeline,NeoGeographyToolkit/StereoPipeline,ScottMcMichael/StereoPipeline,aaronknister/StereoPipeline,oleg-alexandrov/StereoPipeline,oleg-alexandrov/StereoPipeline,njwilson23/StereoPipeline,NeoGeographyToolkit/StereoPipeline,NeoGeographyToolkit/StereoPipeline,ScottMcMichael/StereoPipeline,oleg-alexandrov/StereoPipeline,ScottMcMichael/StereoPipeline,DougFirErickson/StereoPipeline,aaronknister/StereoPipeline,ScottMcMichael/StereoPipeline,njwilson23/StereoPipeline,oleg-alexandrov/StereoPipeline,aaronknister/StereoPipeline,njwilson23/StereoPipeline,DougFirErickson/StereoPipeline,aaronknister/StereoPipeline,DougFirErickson/StereoPipeline