patch 8.2.1368: Vim9: no error for missing white space around operator

Problem:    Vim9: no error for missing white space around operator.
Solution:   Check for white space around <, !=, etc.
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index ab274a1..aa7aed7 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -726,6 +726,38 @@
     set noignorecase
   END
   CheckScriptSuccess(lines)
+
+  # check missing white space
+  lines =<< trim END
+    vim9script
+    echo 2>3
+  END
+  CheckScriptFailure(lines, 'E1004:')
+  lines =<< trim END
+    vim9script
+    echo 2 >3
+  END
+  CheckScriptFailure(lines, 'E1004:')
+  lines =<< trim END
+    vim9script
+    echo 2> 3
+  END
+  CheckScriptFailure(lines, 'E1004:')
+  lines =<< trim END
+    vim9script
+    echo 2!=3
+  END
+  CheckScriptFailure(lines, 'E1004:')
+  lines =<< trim END
+    vim9script
+    echo 2 !=3
+  END
+  CheckScriptFailure(lines, 'E1004:')
+  lines =<< trim END
+    vim9script
+    echo 2!= 3
+  END
+  CheckScriptFailure(lines, 'E1004:')
 enddef
 
 func Test_expr4_fails()