Clarify the ownership model of LLVMContext and Module. Namely, contexts own

modules are instantiated in them.  If the context is deleted, all of its owned
modules are also deleted.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113374 91177308-0d34-0410-b5e6-96231b3b80d8

lib/VMCore/Module.cpp

@@ -62,9 +62,11 @@ Module::Module(StringRef MID, LLVMContext& C)
   ValSymTab = new ValueSymbolTable();
   TypeSymTab = new TypeSymbolTable();
   NamedMDSymTab = new StringMap<NamedMDNode *>();
+  Context.addModule(this);
 }
 
 Module::~Module() {
+  Context.removeModule(this);
   dropAllReferences();
   GlobalList.clear();
   FunctionList.clear();