[llvm] [Attributor] Do not optimize away externally_initialized loads. (PR #128170)

[Matt Arsenault via llvm-commits]

================
@@ -260,7 +260,8 @@ AA::getInitialValueForObj(Attributor &A, const AbstractAttribute &QueryingAA,
       return nullptr;
   } else {
     if (!GV->hasLocalLinkage() &&
-        (GV->isInterposable() || !(GV->isConstant() && GV->hasInitializer())))
+        (GV->isInterposable() || GV->isExternallyInitialized() ||
+         !(GV->isConstant() && GV->hasInitializer())))
----------------
arsenm wrote:

demorgan condition. Or just fix this to use hasDefinitiveInitializer 

https://github.com/llvm/llvm-project/pull/128170