rewrite DwarfEHPrepare to use SSAUpdater to promote its allocas
instead of PromoteMemToReg.  This allows it to stop using DF and DT,
eliminating a computation of DT and DF from clang -O3.  Clang is now
down to 2 runs of DomFrontier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112457 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed