Keep track of fallthrough edges in PatmosFunctionSplitter, do not rely on successors
Fixed CalleeSavedReg spilling of predicate regs

* since pred regs alias SZ, they were spilled twice;
  skip pred regs now
* minor refactoring, RFP<-RSP copying and RFB assignment
  now done in processFunctionBeforeCalleeSavedScan()
Merge branch 'master' into patmos_32_merged