From Kalle Raiskila:

"the bigstack patch for SPU, with testcase. It is essentially the patch committed as 97091, and reverted as 97099, but with the following additions:
-in vararg handling, registers are marked to be live, to not confuse the register scavenger
-function prologue and epilogue are not emitted, if the stack size is 16. 16 means it is empty - there is only the register scavenger emergency spill slot, which is not used as there is no stack."

llvm-svn: 99819