Users reported issue with fetching gcc-3.4.5-r1, see http://pastebin.com/673426, worked the same way for me. It seems that either mirrors still have the old file or it wasn't uploaded at all.
Quick fix for users is to either apply  or just do `rm /usr/portage/sys-devel/gcc/files/digest-gcc-3.4.5-r1 && ebuild /usr/portage/sys-devel/gcc/gcc-3.4.5-r1.ebuild digest`.
*** Bug 130757 has been marked as a duplicate of this bug. ***
Fixed the digest, thanks.
*** Bug 130775 has been marked as a duplicate of this bug. ***
Verified, digest is fine.