[llvm] [FuncSpec] Query SCCPSolver in more places (PR #114964)

[Alexandros Lamprineas via llvm-commits]

================
@@ -312,10 +317,10 @@ bool InstCostVisitor::discoverTransitivelyIncomingValues(
 
       // Disregard self-references and dead incoming values.
       if (auto *Inst = dyn_cast<Instruction>(V))
-        if (Inst == PN || DeadBlocks.contains(PN->getIncomingBlock(I)))
----------------
labrinea wrote:

> It's maybe confusing that this function is named the same as the SCCPSolver member function, but this change is to make us dispatch to InstCostVisitor::isBlockExecutable

Ah right, excuse me I had forgotten that. Then it makes sense. Can you use that function inside canEliminateSuccessor then?

https://github.com/llvm/llvm-project/pull/114964