Add a flag to Module::getGlobalVariable to allow it to return vars with
internal linkage.

Patch provided by Evan Jones, thanks!

llvm-svn: 24604
diff --git a/llvm/lib/VMCore/Module.cpp b/llvm/lib/VMCore/Module.cpp
index a554d8e..de63b4ba 100644
--- a/llvm/lib/VMCore/Module.cpp
+++ b/llvm/lib/VMCore/Module.cpp
@@ -206,17 +206,17 @@
 //
 
 /// getGlobalVariable - Look up the specified global variable in the module
-/// symbol table.  If it does not exist, return null.  Note that this only
-/// returns a global variable if it does not have internal linkage.  The type
-/// argument should be the underlying type of the global, ie, it should not
-/// have the top-level PointerType, which represents the address of the
-/// global.
+/// symbol table.  If it does not exist, return null.  The type argument
+/// should be the underlying type of the global, i.e., it should not have
+/// the top-level PointerType, which represents the address of the global.
+/// If AllowInternal is set to true, this function will return types that
+/// have InternalLinkage. By default, these types are not returned.
 ///
 GlobalVariable *Module::getGlobalVariable(const std::string &Name,
-                                          const Type *Ty) {
+                                          const Type *Ty, bool AllowInternal) {
   if (Value *V = getSymbolTable().lookup(PointerType::get(Ty), Name)) {
     GlobalVariable *Result = cast<GlobalVariable>(V);
-    if (!Result->hasInternalLinkage())
+    if (AllowInternal || !Result->hasInternalLinkage())
       return Result;
   }
   return 0;