Implement .cfi_escape. Patch by Brian Anderson!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147352 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 46ab65f..38c78cd 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -987,6 +987,10 @@
     Streamer.EmitULEB128IntValue(Reg);
     return;
   }
+  case MCCFIInstruction::Escape:
+    if (VerboseAsm) Streamer.AddComment("Escape bytes");
+    Streamer.EmitBytes(Instr.getValues(), 0);
+    return;
   }
   llvm_unreachable("Unhandled case in switch");
 }