Make DeclContext::getLexicalParent reuse DeclContext::getParent.

llvm-svn: 59651
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index c0655cf..2bfb5ae 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/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();
 }