testdriver: delete unused ways

And mention more prominently that `-DDEBUG` and tests that call
`compiler_stats_num_fields` don't play well together

Reviewed By: austin

Differential Revision: https://phabricator.haskell.org/D799

1 files changed, 2 insertions, 1 deletions

diff --git a/validate b/validate
index 95d3af5eae..647bb45a03 100755
--- a/validate
+++ b/validate
@@ -20,7 +20,8 @@ Flags:
                     HTML generated here: testsuite/hpc_output/hpc_index.html
   --normal          Default settings
   --fast            Omit dyn way, omit binary distribution
-  --slow            Build stage2 with -DDEBUG.
+  --slow            Build stage2 with -DDEBUG. Skips tests that call
+                    `compiler_stats_num_field`.
                     2008-07-01: 14% slower than the default.
   --dph:            Also build libraries/dph and run associated tests.
   --help            shows this usage help.