Add "Restored" flag to CalleeSavedInfo

The liveness-tracking code assumes that the registers that were saved
in the function's prolog are live outside of the function. Specifically,
that registers that were saved are also live-on-exit from the function.
This isn't always the case as illustrated by the LR register on ARM.

Differential Revision: https://reviews.llvm.org/D36160

llvm-svn: 310619
diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.h b/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
index d43a176..91c5a5d 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
@@ -35,7 +35,7 @@
                                  const TargetRegisterInfo *TRI) const override;
   bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MBBII,
-                                   const std::vector<CalleeSavedInfo> &CSI,
+                                   std::vector<CalleeSavedInfo> &CSI,
                                    const TargetRegisterInfo *TRI) const
     override;
   void processFunctionBeforeFrameFinalized(MachineFunction &MF,