change checking for auto-init metadata to use equalsStr instead of …

…casing MDOperand nodes.

Since `MD_annotation` metadata now supports having mutliple strings in the annotation node. casing Operand to string directly will cause a crash. When checking if `MDOperand` equals str you can use `equalsStr` method.

Reviewed By: serge-sans-paille

Differential Revision: https://reviews.llvm.org/D152372

llvm/lib/Transforms/Utils/MoveAutoInit.cpp

@@ -40,9 +40,7 @@ static cl::opt<unsigned> MoveAutoInitThreshold(
 static bool hasAutoInitMetadata(const Instruction &I) {
   return I.hasMetadata(LLVMContext::MD_annotation) &&
          any_of(I.getMetadata(LLVMContext::MD_annotation)->operands(),
-                [](const MDOperand &Op) {
-                  return cast<MDString>(Op.get())->getString() == "auto-init";
-                });
+                [](const MDOperand &Op) { return Op.equalsStr("auto-init"); });
 }
 
 static std::optional<MemoryLocation> writeToAlloca(const Instruction &I) {