As we already return true from needsAggressiveScheduling() for the most recent hardware it would be cleaner to just return true for all PowerPC hardware.
Three tests were deleted because they were looking for correct spill behavior however with the use of the machine scheduler the spill is not longer required and therefore cannot be checked for correctness
2011-12-05-NoSpillDupCR.ll save-cr-ppc32svr4.ll save-crbp-ppc32svr4.ll
Also, the following test ppc64-gep-opt.ll was cut down significantly because the removal of needsAggressiveScheduling() also means that PPCSubtarget::useAA() always returns true. That test checked with and without AA. I have removed the without AA portion of the test.