IR: Call dropAllReferences from GlobalVariable's destructor.

We were previously failing to do this and as a result failing to drop
attached metadata.

Not sure if there's a good way to test this. An in-progress patch exposed this
problem by allocating a GlobalVariable at the same address as a previously
allocated GlobalVariable.

Differential Revision: http://reviews.llvm.org/D21109

llvm-svn: 272077

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/include/llvm/IR/GlobalVariable.h b/llvm/include/llvm/IR/GlobalVariable.h
index 7bc528775dd..ebeb635468d 100644
--- a/llvm/include/llvm/IR/GlobalVariable.h
+++ b/llvm/include/llvm/IR/GlobalVariable.h
@@ -65,6 +65,8 @@ public:
                  bool isExternallyInitialized = false);
 
   ~GlobalVariable() override {
+    dropAllReferences();
+
     // FIXME: needed by operator delete
     setGlobalVariableNumOperands(1);
   }