To workaround a gcc-4.1 visibility bug we disable the pragma part.
Created attachment 78179 [details, diff] workaround gcc4 visibility bug disable pragma part
I am not gonna support 4.1 until it is alot closer to being a final release.
That is absolutely fine to me. It was not meant to be included into portage. More it was for gcc-4.1 testers to add this if they hit a strange linker issue during firefox build. Will be fixed upstream.