testsuite: Add haddock perf test output to gitignore

[skip ci]

testsuite: Add haddock perf test output to gitignore
[skip ci]
c05ca251 · Ben Gamari · Marge Bot · 9b4ff57d · c05ca251
Commit c05ca251 authored Jun 10, 2019 by Ben Gamari 🐢 Committed by Marge Bot Jun 12, 2019
--- a/testsuite/tests/perf/haddock/.gitignore
+++ b/testsuite/tests/perf/haddock/.gitignore
+# RTS performance metrics output from haddock perf tests
+*.t