[WIN] Fix error C7555: use of designated initializers requires at least '/std:c++20'

Signed-off-by: Whitney Tsang <whitney.tsang@intel.com>

Author: whitneywhtsang

third_party/nvidia/lib/TritonNVIDIAGPUToLLVM/DotOpToLLVM/MMAHelpers.h

@@ -339,12 +339,12 @@ class DotOpMmaSmemLoader : public DotOpMmaMemLoader {
             default:
               llvm_unreachable("Unsupported swizzling size.");
             }
-            return {.descriptor = desc,
-                    .swizzlingByteWidth = swizzling,
-                    .bitwidth = bitwidth,
-                    .twoCTAs = twoCTAs,
-                    .transposed = transposed,
-                    .fp4Padded = fp4Padded};
+            return {/* .descriptor = */ desc,
+                    /* .swizzlingByteWidth = */ swizzling,
+                    /* .bitwidth = */ bitwidth,
+                    /* .twoCTAs = */ twoCTAs,
+                    /* .transposed = */ transposed,
+                    /* .fp4Padded = */ fp4Padded};
           }
         }
       }