[MIR] Add support for the frame-destroy MachineInstr flag

We are printing / parsing the `frame-setup` MachineInstr flag but not
the `frame-destroy` one.

Differential Revision: https://reviews.llvm.org/D41509

llvm-svn: 322071
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index f91cca6..cd3ec2e 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -670,6 +670,9 @@
     OS << " = ";
   if (MI.getFlag(MachineInstr::FrameSetup))
     OS << "frame-setup ";
+  else if (MI.getFlag(MachineInstr::FrameDestroy))
+    OS << "frame-destroy ";
+
   OS << TII->getName(MI.getOpcode());
   if (I < E)
     OS << ' ';