[llvm] [Attributor] Prevent infinite loop in AAGlobalValueInfoFloating (PR #94941)

[Vidush Singhal via llvm-commits]

================
@@ -1749,6 +1749,10 @@ bool Attributor::checkForAllCallees(
   return Pred(Callees.getArrayRef());
 }
 
+bool noRevisitUser(const User *user) {
+  return isa<PHINode>(user) || !isa<Instruction>(user);
----------------
vidsinghal wrote:

I'd recommend to prevent adding a phi or instruction on the worklist to begin with. 
The AddUsers function can have this check before the User is pushed on the worklist. 
For instance these checks can go here: https://github.com/llvm/llvm-project/blob/530ec6d11462f7801c9cfc819b0deda876ca3d2d/llvm/lib/Transforms/IPO/Attributor.cpp#L1784


https://github.com/llvm/llvm-project/pull/94941