Merge r329657.

This is the main patch that introduced the new EFLAGS lowering infrastructure.
All the source merges were clean, but the tests required help to merge.
Specifically, I had to regenerate the CHECK lines in the tests (using the trunk
update_llc_test_checks.py script) because trunk has copy propagation that the
branch doesn't. I also had to update the MIR test to use the old MIR syntax for
physical registers (%name instead of $name).

llvm-svn: 332933