SuccessChanges

Summary

  1. Revert "[LoopDeletion] Break backedge of loops when known not taken" (details)
  2. CodeGen: Use Register (details)
Commit 7c63aac7bd4e5ce3402f2ef7c1d5b66047230147 by listmail
Revert "[LoopDeletion] Break backedge of loops when known not taken"

This reverts commit dd6bb367d19e3bf18353e40de54d35480999a930.

Multi-stage builders are showing an assertion failure w/LCSSA not being preserved on entry to IndVars.  Reason isn't clear, reverting while investigating.
The file was removedllvm/test/Transforms/LoopDeletion/zero-btc.ll
The file was modifiedllvm/test/Transforms/IndVarSimplify/X86/pr45360.ll
The file was modifiedllvm/lib/Transforms/Scalar/LoopDeletion.cpp
The file was modifiedllvm/test/Transforms/LoopDeletion/update-scev.ll
The file was modifiedllvm/lib/Transforms/Utils/LoopUtils.cpp
The file was modifiedllvm/test/Transforms/IndVarSimplify/exit_value_test2.ll
The file was modifiedllvm/include/llvm/Transforms/Utils/LoopUtils.h
Commit d8938c8bb5479b168d27d3e161cb3a53e8ff09f0 by Matthew.Arsenault
CodeGen: Use Register
The file was modifiedllvm/lib/Target/RISCV/RISCVFrameLowering.cpp
The file was modifiedllvm/include/llvm/CodeGen/MachineFrameInfo.h