patch 8.2.1218: Vim9: cannot use 'text'->func()

Problem:    Vim9: cannot use 'text'->func().
Solution:   Recognize string at start of command.
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 8214675..f9c5a2a 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -355,6 +355,15 @@
     ("some")->MyFunc()
     assert_equal('some', var)
 
+    'asdfasdf'->MyFunc()
+    assert_equal('asdfasdf', var)
+
+    def UseString()
+      'xyork'->MyFunc()
+    enddef
+    UseString()
+    assert_equal('xyork', var)
+
     MyFunc(
         'continued'
         )