This is a deliberate error added in 23.2 for gcc-4.5.0, most likely due to bug #317187. I'm not asking this be fixed or anything, just please leave this bug open so we have an accurate idea of what packages still have issues.
Created attachment 231285 [details, diff] ebuild patched to compile emacs with gcc-4.5 Why not fix it? ;-)
(In reply to comment #1) > Why not fix it? ;-) GCC 4.5 is still hardmasked, therefore I see no reason for adding such workarounds to the Emacs ebuild.
Fixed in 4.5.1.