Add a way to print debug counters without exiting

I am trying to study debug counters inside a Rails application.
Accessing debug counters by killing the process is hard because child
processes don't get the same TRAP as the parent, and Rails seems to
intercept calls to `exit`.  Adding this method lets me print the debug
counters when I want (at the end of requests for example)

1 files changed, 7 insertions, 0 deletions

diff --git a/debug_counter.c b/debug_counter.c
index f17fb1c488..f17b3b4d7c 100644
--- a/debug_counter.c
+++ b/debug_counter.c
@@ -44,6 +44,13 @@ rb_debug_counter_show_results(const char *msg)
 }
 
 VALUE
+rb_debug_counter_show(void)
+{
+    rb_debug_counter_show_results("method call");
+    return Qnil;
+}
+
+VALUE
 rb_debug_counter_reset(void)
 {
     for (int i = 0; i < RB_DEBUG_COUNTER_MAX; i++) {