Suppress exception message in finalizer [Feature #17798]

gc.c

@@ -3990,7 +3990,7 @@ run_single_final(VALUE cmd, VALUE objid)
 static void
 warn_exception_in_finalizer(rb_execution_context_t *ec, VALUE final)
 {
-    if (final != Qundef) {
+    if (final != Qundef && !NIL_P(ruby_verbose)) {
 	VALUE errinfo = ec->errinfo;
 	rb_warn("Exception in finalizer %+"PRIsVALUE, final);
 	rb_ec_error_print(ec, errinfo);

test/ruby/test_gc.rb

@@ -459,7 +459,7 @@ class TestGc < Test::Unit::TestCase
         obj = nil
       }
     }
-    GC.start
+    EnvUtil.suppress_warning {GC.start}
     skip "finalizers did not get run" if result.empty?
     assert_equal([:c1, :c2], result)
   end
@@ -482,7 +482,7 @@ class TestGc < Test::Unit::TestCase
         obj = nil
       }
     }
-    GC.start
+    EnvUtil.suppress_warning {GC.start}
     skip "finalizers did not get run" if @result.empty?
     assert_equal([:c1, :c2], @result)
   end