Tweaked Apple gcc 4.2 check
Tweaked Apple gcc 4.2 check

Comments say the hack is for apple-gcc-4.2,
but clang also identifies itself as such.
Make the check more exact.

Change-Id: Ic4a9adfa1fd60d74b5e8e4cea421757e07b1bb89

demarle/VTK,biddisco/VTK,sankhesh/VTK,biddisco/VTK,johnkit/vtk-dev,msmolens/VTK,sumedhasingla/VTK,jmerkow/VTK,sankhesh/VTK,ashray/VTK-EVM,hendradarwin/VTK,hendradarwin/VTK,berendkleinhaneveld/VTK,jmerkow/VTK,msmolens/VTK,berendkleinhaneveld/VTK,keithroe/vtkoptix,biddisco/VTK,berendkleinhaneveld/VTK,keithroe/vtkoptix,keithroe/vtkoptix,biddisco/VTK,candy7393/VTK,johnkit/vtk-dev,candy7393/VTK,keithroe/vtkoptix,demarle/VTK,johnkit/vtk-dev,johnkit/vtk-dev,candy7393/VTK,jmerkow/VTK,jmerkow/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,candy7393/VTK,mspark93/VTK,ashray/VTK-EVM,sankhesh/VTK,mspark93/VTK,sumedhasingla/VTK,SimVascular/VTK,biddisco/VTK,candy7393/VTK,mspark93/VTK,SimVascular/VTK,ashray/VTK-EVM,candy7393/VTK,hendradarwin/VTK,keithroe/vtkoptix,sankhesh/VTK,sumedhasingla/VTK,SimVascular/VTK,gram526/VTK,berendkleinhaneveld/VTK,ashray/VTK-EVM,gram526/VTK,keithroe/vtkoptix,gram526/VTK,jmerkow/VTK,ashray/VTK-EVM,sankhesh/VTK,keithroe/vtkoptix,msmolens/VTK,msmolens/VTK,johnkit/vtk-dev,johnkit/vtk-dev,msmolens/VTK,mspark93/VTK,msmolens/VTK,SimVascular/VTK,demarle/VTK,sumedhasingla/VTK,msmolens/VTK,hendradarwin/VTK,mspark93/VTK,demarle/VTK,SimVascular/VTK,sankhesh/VTK,biddisco/VTK,berendkleinhaneveld/VTK,sumedhasingla/VTK,sumedhasingla/VTK,gram526/VTK,mspark93/VTK,berendkleinhaneveld/VTK,hendradarwin/VTK,sumedhasingla/VTK,demarle/VTK,hendradarwin/VTK,candy7393/VTK,gram526/VTK,sankhesh/VTK,hendradarwin/VTK,SimVascular/VTK,gram526/VTK,SimVascular/VTK,jmerkow/VTK,SimVascular/VTK,ashray/VTK-EVM,biddisco/VTK,msmolens/VTK,gram526/VTK,keithroe/vtkoptix,demarle/VTK,ashray/VTK-EVM,jmerkow/VTK,gram526/VTK,sumedhasingla/VTK,demarle/VTK,candy7393/VTK,johnkit/vtk-dev,mspark93/VTK,sankhesh/VTK,mspark93/VTK,demarle/VTK,ashray/VTK-EVM