getPristineRegs is not accurately considering shrink wrapping puts
registers not saved in certain blocks. Use explicit getCalleeSavedInfo
and isLiveIn instead.

This fixes pr32292.

Patch by Tim Shen!

llvm-svn: 299124
diff --git a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index a60a43a..955524c 100644
--- a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -166,7 +166,8 @@
   for (const MCPhysReg *I = MF.getRegInfo().getCalleeSavedRegs(); *I;
        ++I) {
     unsigned Reg = *I;
-    if (!IsReturnBlock && !Pristine.test(Reg)) continue;
+    if (!IsReturnBlock && !(Pristine.test(Reg) || BB->isLiveIn(Reg)))
+      continue;
     for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
       unsigned AliasReg = *AI;
       State->UnionGroups(AliasReg, 0);