Rename p_free_tree() to p_tree_delete()

spec/test_tree_delete_token_node_memory.c

@@ -0,0 +1,20 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "ab";
+    p_context_t * context;
+    context = p_context_new((uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(context));
+    Start * start = p_result(context);
+    assert(start->a != NULL);
+    assert(*start->a->pvalue == 1);
+    assert(start->b != NULL);
+    assert(*start->b->pvalue == 2);
+
+    p_tree_delete(start);
+    p_context_delete(context);
+}