Constified mjit_init

mjit.c

@@ -741,7 +741,7 @@ split_flags(const char *flags)
 // processing ISeqs.  The function should be called first for using MJIT.
 // If everything is successful, MJIT_INIT_P will be TRUE.
 void
-mjit_init(struct mjit_options *opts)
+mjit_init(const struct mjit_options *opts)
 {
     mjit_opts = *opts;
     mjit_enabled = true;

mjit.h

@@ -80,7 +80,7 @@ extern void rb_mjit_recompile_iseq(const rb_iseq_t *iseq);
 RUBY_SYMBOL_EXPORT_END
 
 extern bool mjit_compile(FILE *f, const rb_iseq_t *iseq, const char *funcname);
-extern void mjit_init(struct mjit_options *opts);
+extern void mjit_init(const struct mjit_options *opts);
 extern void mjit_gc_start_hook(void);
 extern void mjit_gc_exit_hook(void);
 extern void mjit_free_iseq(const rb_iseq_t *iseq);