Make DeclContext::getLexicalParent reuse DeclContext::getParent.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59651 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index c0655cf..2bfb5ae 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -365,8 +365,5 @@
 const DeclContext *DeclContext::getLexicalParent() const {
   if (const ScopedDecl *SD = dyn_cast<ScopedDecl>(this))
     return SD->getLexicalDeclContext();
-  else if (const BlockDecl *BD = dyn_cast<BlockDecl>(this))
-    return BD->getParentContext();
-  else
-    return NULL;
+  return getParent();
 }