Do not check pending interrupts when running finalizers

This fixes cases where exceptions raised using Thread#raise are
swallowed by finalizers and not delivered to the running thread.

This could cause issues with finalizers that rely on pending interrupts,
but that case is expected to be rarer.

Fixes [Bug #13876]
Fixes [Bug #15507]

Co-authored-by: Koichi Sasada <ko1@atdot.net>

gc.c

@@ -4088,10 +4088,14 @@ static void
 finalize_deferred(rb_objspace_t *objspace)
 {
     VALUE zombie;
+    rb_execution_context_t *ec = GET_EC();
+    ec->interrupt_mask |= PENDING_INTERRUPT_MASK;
 
     while ((zombie = ATOMIC_VALUE_EXCHANGE(heap_pages_deferred_final, 0)) != 0) {
 	finalize_list(objspace, zombie);
     }
+
+    ec->interrupt_mask &= ~PENDING_INTERRUPT_MASK;
 }
 
 static void

test/ruby/test_objectspace.rb

@@ -168,6 +168,31 @@ End
     end;
   end
 
+  def test_finalizer_thread_raise
+    GC.disable
+    fzer = proc do |id|
+      sleep 0.2
+    end
+    2.times do
+      o = Object.new
+      ObjectSpace.define_finalizer(o, fzer)
+    end
+
+    my_error = Class.new(RuntimeError)
+    begin
+      main_th = Thread.current
+      Thread.new do
+        sleep 0.1
+        main_th.raise(my_error)
+      end
+      GC.start
+      puts "After GC"
+      sleep(10)
+      assert(false)
+    rescue my_error
+    end
+  end
+
   def test_each_object
     klass = Class.new
     new_obj = klass.new