Graph reuse (#947)

* Add mainline compatible FA command line option

* Graph reuse: add command line argument to turn it on

* WIP

* This seems to work

* This is perhaps cleaner

* Change the command line option to -gr

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Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>

include/llama.h

@@ -429,6 +429,7 @@ extern "C" {
         bool fused_up_gate;     // whether to use fused up/gate op [EXPERIMENTAL]
         bool fused_mmad;        // whether to use fused mul+multi_add op [EXPERIMENTAL]
         bool rope_cache;        // whether to use RoPE cache [EXPERIMENTAL]
+        bool graph_reuse;       // whether to reuse graphs when possible [EXPERIMENTAL]
         int  min_experts;
         float thresh_experts;
         bool only_active_experts;