Add ComputeBudget tuner (#12476)

programs/bpf/c/src/tuner/tuner.c

@@ -0,0 +1,23 @@
+/**
+ * @brief Compute budget tuner program.  Spins in a loop consuming the entire
+ * budget, used by the tuner bench test to tune the compute budget costs.
+ *
+ * Care should be taken because the compiler might optimize out the mechanism
+ * you are trying to tune.
+ */
+
+#include <solana_sdk.h>
+
+extern uint64_t entrypoint(const uint8_t *input) {
+  uint8_t *val = (uint8_t *)input;
+  for (uint64_t i = 0; i < UINT64_MAX; i++) {
+
+    // Uncomment for raw compute
+    {
+      if (*val != 0) {
+        *val = *val + 1;
+      }
+    }
+  }
+  return *val;
+}