ggml: add graph_reused (#21764)

* ggml: add graph_reused

* use versioning instead of reuse flag

* increment version with atomic

* use top bits for split numbering

* add assert

* move counter to ggml.c

* set uid in split_graph only

* fix windows

* address further review comments

* get next_uid rather than doing bit manipulation

* rename + add comment about uid

ggml/src/ggml-cuda/common.cuh

@@ -1186,6 +1186,7 @@ struct ggml_cuda_graph {
     std::vector<cudaGraphNode_t> nodes;
     bool disable_due_to_gpu_arch = false;
     bool warmup_complete = false;
+    uint64_t uid = 0;
     struct node_properties {
         ggml_tensor node;
         void *   node_src_data_ptrs[GGML_MAX_SRC];