[mlir][vector][spirv] Fix a crash in VectorLoadOpConverter (#149964)

This PR adds null check for `spirvVectorType` in VectorLoadOpConverter
to prevent a crash. Fixes #149956.

Author: CoTinker

mlir/lib/Conversion/VectorToSPIRV/VectorToSPIRV.cpp

@@ -793,6 +793,9 @@ struct VectorLoadOpConverter final
     // Use the converted vector type instead of original (single element vector
     // would get converted to scalar).
     auto spirvVectorType = typeConverter.convertType(vectorType);
+    if (!spirvVectorType)
+      return rewriter.notifyMatchFailure(loadOp, "unsupported vector type");
+
     auto vectorPtrType = spirv::PointerType::get(spirvVectorType, storageClass);
 
     // For single element vectors, we don't need to bitcast the access chain to

mlir/test/Conversion/VectorToSPIRV/vector-to-spirv.mlir

@@ -1161,3 +1161,15 @@ func.func @vector_store_2d(%arg0 : memref<4x4xf32, #spirv.storage_class<StorageB
 }
 
 } // end module
+
+// -----
+
+// Ensure the case without module attributes not crash.
+
+// CHECK-LABEL: @vector_load
+//       CHECK:   vector.load
+func.func @vector_load(%arg0 : memref<4xf32, #spirv.storage_class<StorageBuffer>>) -> vector<4xf32> {
+  %idx = arith.constant 0 : index
+  %0 = vector.load %arg0[%idx] : memref<4xf32, #spirv.storage_class<StorageBuffer>>, vector<4xf32>
+  return %0: vector<4xf32>
+}