metal : support argsort for ne00 > 1024 (#17247)

* metal : refactor argsort

* cont : sort chunks

* cont : merge sorted buckets

* cont : cleanup

ggml/src/ggml-metal/ggml-metal.cpp

@@ -197,6 +197,10 @@ static size_t ggml_backend_metal_buffer_type_get_alloc_size(ggml_backend_buffer_
                 res += ggml_metal_op_flash_attn_ext_extra_blk(tensor);
                 res += ggml_metal_op_flash_attn_ext_extra_tmp(tensor);
             } break;
+        case GGML_OP_ARGSORT:
+            {
+                res *= 2;
+            } break;
         default:
             break;
     }