Revert "Revert r166370 and r166540 now that Xcode 4.6 has been available for a while."

This reverts commit 176887.  Nico asked for more time to move to Xcode 4.6.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@176892 91177308-0d34-0410-b5e6-96231b3b80d8
Driver: -ccc-install-dir should affect cc1 -resource-dir

-ccc-install-dir is supposed to cause the compiler to behave as-if it
were installed in the indicated location. It almost does, but misses
anything that's relying on the resource directory (libc++ header search,
in particular). The resource dir is resolved too early, before command
line args are handled.

The fix is simply to move handling of the resource dir until after we
know if a -ccc-install-dir is present.

rdar://13402696

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@176894 91177308-0d34-0410-b5e6-96231b3b80d8
Force column info to be generated for call expressions so we can
differentiate multiple inlined call sites on the same line
in the debug info.

Fixes rdar://problem/13036237

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@176895 91177308-0d34-0410-b5e6-96231b3b80d8