When destroying a translation unit, deallocate its owned declarations in reverse order, because there may be dependencies among the declarations.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@58244 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/TranslationUnit.cpp b/lib/AST/TranslationUnit.cpp
index 659aa06..42b7cea 100644
--- a/lib/AST/TranslationUnit.cpp
+++ b/lib/AST/TranslationUnit.cpp
@@ -33,7 +33,9 @@
 TranslationUnit::~TranslationUnit() {
   if (OwnsDecls) {
     llvm::DenseSet<Decl*> Killed;
-    for (iterator I=begin(), E=end(); I!=E; ++I) {
+    for (std::vector<Decl*>::reverse_iterator I=TopLevelDecls.rbegin(), 
+                                              E=TopLevelDecls.rend(); 
+         I!=E; ++I) {
       if (Killed.count(*I)) continue;
 
       Killed.insert(*I);