[Mono-osx] can't build 1.2 on Intel

[Benjamin Reed]

It looks like the build is freezing up:

---(snip!)---
Making all in runtime
if test -w ../mcs; then :; else chmod -R +w ../mcs; fi
cd ../mcs && make PROFILES='default net_2_0' CC='gcc' all-profiles
make profile-do--default--all profile-do--net_2_0--all
make PROFILE=basic all
---(snip!)---

I've left a build running for an hour and it still just sits there, so
there's definitely something hinky going on, but it's hard to tell
why.  Any ideas?