libgc's all lib is x86, not armv7

[gadmyth]

When I build clojurec on my mac-mini 10.7.5, I found that all is well, but when I sudo run:

cd ~/clojurec/run/ios/; sudo ./bootstrap.sh

I found in libgc.os/lib/, all libxxx.a is x86_64 using lipo to see.

so the clojurec xcode can't build for armv7.