Share lock: more accurate livelock fix for aa598f4

Awaken waiting threads even if the current thread (the previously
exclusive thread) hadn't taken a share lock.

This only happens in code that wasn't run within an executor, since that
always take an outermost share lock.

activesupport/lib/active_support/concurrency/share_lock.rb

@@ -69,7 +69,6 @@ module ActiveSupport
 
             if eligible_waiters?(compatible)
               yield_shares(compatible: compatible, block_share: true) do
-                @cv.broadcast
                 @cv.wait_while { @exclusive_thread || eligible_waiters?(compatible) }
               end
             end
@@ -145,9 +144,9 @@ module ActiveSupport
             end
             compatible |= [false] unless block_share
             @waiting[Thread.current] = [purpose, compatible]
-
-            @cv.broadcast
           end
+
+          @cv.broadcast
         end
 
         begin