[SimplifyCFG] Use Value::hasNUses instead of 'getNumUses() =='. NFCI

getNumUses is linear in the number of uses. Since we're looking for a specific use count, we can use hasNUses which will stop as soon as it determines there are more than N uses instead of walking all of them.

llvm-svn: 343550

llvm/lib/Transforms/Utils/SimplifyCFG.cpp

@@ -2001,7 +2001,7 @@ static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB,
            I = SinkCandidateUseCounts.begin(),
            E = SinkCandidateUseCounts.end();
        I != E; ++I)
-    if (I->first->getNumUses() == I->second) {
+    if (I->first->hasNUses(I->second)) {
       ++SpeculationCost;
       if (SpeculationCost > 1)
         return false;