JIT: Fix TryLowerNegToMulLongOp transformation with HW intrinsics disabled (#93384)

The transform creates a HW intrinsic node, so needs a defensive check
here. The other transform of the same kind, `TryLowerAddSubToMulLongOp`,
already has the check.

Fix #93299

Author: jakobbotsch

src/coreclr/jit/lowerarmarch.cpp

@@ -2887,6 +2887,9 @@ GenTree* Lowering::TryLowerNegToMulLongOp(GenTreeOp* op)
     if (!comp->opts.OptimizationEnabled())
         return nullptr;
 
+    if (!JitConfig.EnableHWIntrinsic())
+        return nullptr;
+
     if (op->isContained())
         return nullptr;