Use isa instead of !dyn_cast (#137344)

Author: arsenm

llvm/lib/IR/Instruction.cpp

@@ -490,7 +490,7 @@ bool Instruction::hasNonDebugLocLoopMetadata() const {
   // the first item because it is a self-reference.
   for (const MDOperand &Op : llvm::drop_begin(LoopMD->operands())) {
     // check for debug location type by attempting a cast.
-    if (!dyn_cast<DILocation>(Op)) {
+    if (!isa<DILocation>(Op)) {
       return true;
     }
   }

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -8751,7 +8751,7 @@ foldBinOpIntoSelectIfProfitable(SDNode *BO, SelectionDAG &DAG,
 
   unsigned ConstSelOpNo = 1;
   unsigned OtherSelOpNo = 2;
-  if (!dyn_cast<ConstantSDNode>(Sel->getOperand(ConstSelOpNo))) {
+  if (!isa<ConstantSDNode>(Sel->getOperand(ConstSelOpNo))) {
     ConstSelOpNo = 2;
     OtherSelOpNo = 1;
   }

llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp

@@ -1656,7 +1656,7 @@ class StrlenVerifier {
       // We only want RecAddExpr with recurrence step that is constant. This
       // is good enough for all the idioms we want to recognize. Later we expand
       // and materialize the recurrence as {base,+,a} -> (base + a * strlen)
-      if (!dyn_cast<SCEVConstant>(AddRecEv->getStepRecurrence(*SE)))
+      if (!isa<SCEVConstant>(AddRecEv->getStepRecurrence(*SE)))
         return false;
     }