Make LoadInterlockAwareMonitor work in Ruby 2.7

Currently `LoadInterlockAwareMonitorTest` does not pass with Ruby 2.7 [1].
This is due to the refactoring of the `monitor` done in Ruby 2.7 [2].

With this refactoring, the behavior of the method has changed from the
expected behavior in `LoadInterlockAwareMonitor`.

This patch also overwrites `synchronize` so that
`LoadInterlockAwareMonitor` works as expected.

[1]: https://buildkite.com/rails/rails/builds/65877#eec47af5-7595-47cb-97c0-30c589716176/996-2743
[2]: https://bugs.ruby-lang.org/issues/16255

activesupport/lib/active_support/concurrency/load_interlock_aware_monitor.rb

@@ -7,11 +7,29 @@ module ActiveSupport
     # A monitor that will permit dependency loading while blocked waiting for
     # the lock.
     class LoadInterlockAwareMonitor < Monitor
+      EXCEPTION_NEVER = { Exception => :never }.freeze
+      EXCEPTION_IMMEDIATE = { Exception => :immediate }.freeze
+      private_constant :EXCEPTION_NEVER, :EXCEPTION_IMMEDIATE
+
       # Enters an exclusive section, but allows dependency loading while blocked
       def mon_enter
         mon_try_enter ||
           ActiveSupport::Dependencies.interlock.permit_concurrent_loads { super }
       end
+
+      def synchronize
+        Thread.handle_interrupt(EXCEPTION_NEVER) do
+          mon_enter
+
+          begin
+            Thread.handle_interrupt(EXCEPTION_IMMEDIATE) do
+              yield
+            end
+          ensure
+            mon_exit
+          end
+        end
+      end
     end
   end
 end