Make this use a public accessor too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141752 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Analysis/DebugInfo.h b/include/llvm/Analysis/DebugInfo.h
index 402975b..9a53c4d 100644
--- a/include/llvm/Analysis/DebugInfo.h
+++ b/include/llvm/Analysis/DebugInfo.h
@@ -707,7 +707,7 @@
   class DILexicalBlockFile : public DIScope {
   public:
     explicit DILexicalBlockFile(const MDNode *N = 0) : DIScope(N) {}
-    DIScope getContext() const { return getScope().getFieldAs<DIScope>(1); }
+    DIScope getContext() const { return getScope().getContext(); }
     unsigned getLineNumber() const { return getScope().getLineNumber(); }
     unsigned getColumnNumber() const { return getScope().getColumnNumber(); }
     StringRef getDirectory() const {