[llvm] Fix stack overflow in allPathsGoThroughCold past 6b11573b8c5e (PR #106384)

[via llvm-commits]

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@@ -1762,54 +1763,53 @@ static void addNoReturnAttrs(const SCCNodeSet &SCCNodes,
   }
 }
 
-static bool
-allBBPathsGoThroughCold(BasicBlock *BB,
-                        SmallDenseMap<BasicBlock *, bool, 16> &Visited) {
-  // If BB contains a cold callsite this path through the CG is cold.
-  // Ignore whether the instructions actually are guranteed to transfer
-  // execution. Divergent behavior is considered unlikely.
-  if (any_of(*BB, [](Instruction &I) {
-        if (auto *CB = dyn_cast<CallBase>(&I))
-          return CB->hasFnAttr(Attribute::Cold);
-        return false;
-      })) {
-    Visited[BB] = true;
-    return true;
-  }
-
-  auto Succs = successors(BB);
-  // We found a path that doesn't go through any cold callsite.
-  if (Succs.empty())
-    return false;
+static bool allPathsGoThroughCold(Function &F) {
+  SmallDenseMap<BasicBlock *, bool, 16> ColdPaths;
+  ColdPaths[&F.front()] = false;
+  std::stack<BasicBlock *> Jobs;
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goldsteinn wrote:

typically we should just use a `SmallVector<BasicBlock *>` here.

https://github.com/llvm/llvm-project/pull/106384