patch 8.2.2539: Vim9: return from finally block causes a hang

Problem:    Vim9: return from finally block causes a hang.
Solution:   Store both the finally and endtry indexes. (closes #7885)

src/testdir/test_vim9_script.vim

@@ -577,6 +577,16 @@ def Test_try_catch_throw()
     counter += 1
   endfor
   assert_equal(4, counter)
+
+  # return in finally after empty catch
+  def ReturnInFinally(): number
+    try
+    finally
+      return 4
+    endtry
+    return 2
+  enddef
+  assert_equal(4, ReturnInFinally())
 enddef
 
 def Test_cnext_works_in_catch()