Include access modifiers in subprogram metadata IR comment.

Based on code review feedback in r171604 from Chandler Carruth &
Eric Christopher.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171636 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index bec941a..5dd9dd1 100644
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -1122,6 +1122,11 @@
   if (getScopeLineNumber() != getLineNumber())
     OS << " [scope " << getScopeLineNumber() << "]";
 
+  if (isPrivate())
+    OS << " [private]";
+  else if (isProtected())
+    OS << " [protected]";
+
   StringRef Res = getName();
   if (!Res.empty())
     OS << " [" << Res << ']';