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.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
index 0cb2b5a..3183c3a 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -220,7 +220,7 @@
 bool SystemZFrameLowering::
 restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
                             MachineBasicBlock::iterator MBBI,
-                            const std::vector<CalleeSavedInfo> &CSI,
+                            std::vector<CalleeSavedInfo> &CSI,
                             const TargetRegisterInfo *TRI) const {
   if (CSI.empty())
     return false;