[llvm] [DirectX] Convert private global variables to internal linkage during Finalize Linkage pass (PR #146406)

[Justin Bogner via llvm-commits]

================
@@ -18,6 +18,16 @@
 using namespace llvm;
 
 static bool finalizeLinkage(Module &M) {
+  bool MadeChange = false;
+
+  // Convert private global variables to internal linkage.
+  for (GlobalVariable &GV : M.globals()) {
+    if (GV.hasPrivateLinkage()) {
+      GV.setLinkage(GlobalValue::InternalLinkage);
+      MadeChange = true;
+    }
----------------
bogner wrote:

Should we be removing these if `GV.use_empty()` to match what we do with functions? Alternatively, if we don't expect to ever get here with unused private globals, can we `assert(!GV.use_empty())` here? Or is it okay/expected for us to leave unused internal variables around?

https://github.com/llvm/llvm-project/pull/146406