The aggressive anti-dependency breaker can rename the restored callee-
saved registers. To prevent this, mark these registers are live on all
paths to the return/tail-call instructions, and add implicit use operands
for them to these instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270898 91177308-0d34-0410-b5e6-96231b3b80d8
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