patch 8.1.2043: not sufficient testing for quoted numbers

Problem:    Not sufficient testing for quoted numbers.
Solution:   Add a few more test cases.
diff --git a/src/testdir/test_eval_stuff.vim b/src/testdir/test_eval_stuff.vim
index 4e8b782..ec566da 100644
--- a/src/testdir/test_eval_stuff.vim
+++ b/src/testdir/test_eval_stuff.vim
@@ -200,6 +200,9 @@
   call assert_equal(64, 0b1'00'00'00)
   call assert_equal(1048576, 0x10'00'00)
   call assert_equal(1000000, 1'000'000)
+  call assert_equal("1234", execute("echo 1'234")->trim())
+  call assert_equal('1  234', execute("echo 1''234")->trim())
+  call assert_fails("echo 1'''234", 'E115:')
 endfunc
 
 scriptversion 1