OSLExpressionEngine : Work around OIIO macro pollution
OSLExpressionEngine : Work around OIIO macro pollution

hradec/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,hradec/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,hradec/gaffer,hradec/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,hradec/gaffer,andrewkaufman/gaffer