patch 8.0.1518: error messages suppressed after ":silent! try"

Problem:    Error messages suppressed after ":silent! try". (Ben Reilly)
Solution:   Restore emsg_silent before executing :try. (closes #2531)
diff --git a/src/testdir/test_eval_stuff.vim b/src/testdir/test_eval_stuff.vim
index 92e1ec5..1222230 100644
--- a/src/testdir/test_eval_stuff.vim
+++ b/src/testdir/test_eval_stuff.vim
@@ -11,3 +11,17 @@
 func Test_catch_return_with_error()
   call assert_equal(1, s:foo())
 endfunc
+
+func Test_nocatch_restore_silent_emsg()
+  silent! try
+    throw 1
+  catch
+  endtry
+  echoerr 'wrong'
+  let c1 = nr2char(screenchar(&lines, 1))
+  let c2 = nr2char(screenchar(&lines, 2))
+  let c3 = nr2char(screenchar(&lines, 3))
+  let c4 = nr2char(screenchar(&lines, 4))
+  let c5 = nr2char(screenchar(&lines, 5))
+  call assert_equal('wrong', c1 . c2 . c3 . c4 . c5)
+endfunc