Eliminated gcc-specific __builtin_memcpy use
Eliminated gcc-specific __builtin_memcpy use

This file has three implementations of __yy_memcpy:
1) using __builtin_memcpy 2) dead code in #ifndef __cplusplus
and 3) a hand implementation, which I've kept.

Makes VTK more portable to have fewer compiler-specific cases.

Change-Id: I084d3a7d3a12bc6189153ea58f8e43dcc9861e61

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