mxcl/homebrew — pull request #9622 by mikemcquaid (2012-01-16 20:11:51+00:00)
Title: Xcode 4.2 fixes

Use Clang on `fails_with_llvm` and bump the highest seen LLVM version to that from Xcode 4.2.

Again I'm wondering if we should set Clang to the default compiler on Xcode 4.2 or keep using the /usr/bin/{cc,c++} symlinks to decide.