Change the way to truncate i64 to i32 in I64 registers. VE assumed sext values previously. Change it to zext values this time to make it match to the LLVM behaviour. Reviewed By: simoll Differential Revision: https://reviews.llvm.org/D92226
Optimize leaf functions by not generating save/restore for callee saved registers. Update regression tests also. Reviewed By: simoll Differential Revision: https://reviews.llvm.org/D91539
Restructure lit tests to follow downstream Reviewed By: kaz7 Differential Revision: https://reviews.llvm.org/D90468