Revert r240040, "[BranchFolding] Replace custom MachineInstr with MachineInstrExpressionTrait"

It caused different emission between stage2 and stage3. Investigating.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240212 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed