YJIT: Show definedivar exit reasons (#7755)

yjit.rb

@@ -250,6 +250,7 @@ module RubyVM::YJIT
       print_counters(stats, prefix: 'gbpp_', prompt: 'getblockparamproxy exit reasons: ')
       print_counters(stats, prefix: 'getivar_', prompt: 'getinstancevariable exit reasons:')
       print_counters(stats, prefix: 'setivar_', prompt: 'setinstancevariable exit reasons:')
+      print_counters(stats, prefix: 'definedivar_', prompt: 'definedivar exit reasons:')
       print_counters(stats, prefix: 'opt_aref_', prompt: 'opt_aref exit reasons: ')
       print_counters(stats, prefix: 'expandarray_', prompt: 'expandarray exit reasons: ')
       print_counters(stats, prefix: 'opt_getinlinecache_', prompt: 'opt_getinlinecache exit reasons: ')