This bug report tracks issues preventing the removal from the ports tree of GCC versions which are unsupported upstream.
I think I have opened all the bug reports that are necessary.
It might be necessary to open an additional bug report for lang/gcc-ecj45.
I have also forgotten about devel/migw32-gcc, which is unmantained and related to many other mingw32-* ports, all unmaintained. I will soon analyse the situation of those ports as well.
(In reply to Lorenzo Salvadore from comment #3) I am wrong, I had already opened the bug report for mingw32-gcc: it is bug #269662.
Now all bug reports should indeed have been created and focus can be put on fixing them.