introduce any new spilling; it just uses unused registers.

Refactor the SUnit topological sort code out of the RRList scheduler and
make use of it to help with the post-pass scheduler.

llvm-svn: 59999

extend it a bit, and make use of it in all schedulers, to
ensure consistent checking.

llvm-svn: 59689

is currently off by default, and can be enabled with
-disable-post-RA-scheduler=false.

This doesn't have a significant impact on most code yet because it doesn't
yet do anything to address anti-dependencies and it doesn't attempt to
disambiguate memory references. Also, several popular targets
don't have pipeline descriptions yet.

The majority of the changes here are splitting the SelectionDAG-specific
code out of ScheduleDAG, so that ScheduleDAG can be moved to
libLLVMCodeGen.a. The interface between ScheduleDAG-using code and
the rest of the scheduling code is somewhat rough and will evolve.

llvm-svn: 59676

llvm-svn: 55779

llvm-svn: 45972

llvm-svn: 45418

llvm-svn: 39817

Change name of -sched option and DEBUG_TYPE to
pre-RA-sched; adjust testcases.

llvm-svn: 39816