You're confounding issues here. RMS is in the position of a critic of the US government, rightly claiming that, while your country is "free", it installs and supports dictatorships all over the world. It is possible to be unfree, and not support other dictatorships, like Cuba.
It is possible to be both unfree, and support dictatorships, like the USSR. RMS's goal with GCC, is to be like the mythical free country that also supports freedom and discourages dictatorships elsewhere in the world.
In other words, your software can be free, and yet support and aid those who would take your freedom away. This is the claim RMS is making of Clang.