* Enabled R1/R2 application for nodes with infinite spill costs in the Briggs heuristic (made
safe by the changes to the normalization proceedure).
* Removed a redundant header.
llvm-svn: 95973
* Fixed a reduction bug which occasionally led to infinite-cost (invalid)
register allocation solutions despite the existence finite-cost solutions.
* Significantly reduced memory usage (>50% reduction).
* Simplified a lot of the solver code.
llvm-svn: 94514
