RUBY_FREE_ENTER   220 cont.c             RUBY_FREE_ENTER("cont");
RUBY_FREE_ENTER   321 cont.c             RUBY_FREE_ENTER("fiber");
RUBY_FREE_ENTER    72 iseq.c             RUBY_FREE_ENTER("iseq");
RUBY_FREE_ENTER   254 proc.c             RUBY_FREE_ENTER("binding");
RUBY_FREE_ENTER  2047 vm.c               RUBY_FREE_ENTER("vm");
RUBY_FREE_ENTER  2287 vm.c               RUBY_FREE_ENTER("thread");