Add mjit_compile_failures debug counter

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67382 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

debug_counter.h

@@ -275,6 +275,9 @@ RB_DEBUG_COUNTER(mjit_length_unit_queue)
 RB_DEBUG_COUNTER(mjit_length_active_units)
 RB_DEBUG_COUNTER(mjit_length_compact_units)
 
+/* Other MJIT counters */
+RB_DEBUG_COUNTER(mjit_compile_failures)
+
 /* load (not implemented yet) */
 /*
 RB_DEBUG_COUNTER(load_files)

mjit_worker.c

@@ -1241,6 +1241,7 @@ mjit_worker(void)
         if (unit) {
             // JIT compile
             mjit_func_t func = convert_unit_to_func(unit);
+            RB_DEBUG_COUNTER_INC_IF(mjit_compile_failures, func == (mjit_func_t)NOT_COMPILED_JIT_ISEQ_FUNC);
 
             // `mjit_copy_cache_from_main_thread` in `mjit_compile` may wait for a long time
             // and worker may be stopped during the compilation.