PPC/S390: skip slow tests on the simulator

regress-crbug-482998 is skipped and regress-331444 is marked
as slow.

Bug: v8:11875
Change-Id: I01c14dee704c5179d62b79cca0681f833102680d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2996842Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#75481}

test/mjsunit/mjsunit.status

@@ -1104,9 +1104,10 @@
   # take too long with the simulator.
   'regress/regress-1132': [SKIP],
   'regress/regress-740784': [SKIP],
-  'regress/regress-crbug-482998': [PASS, SLOW],
+  'regress/regress-crbug-482998': [SKIP],
   'regress/regress-91008': [PASS, SLOW],
   'regress/regress-779407': [PASS, SLOW],
+  'regress/regress-331444': [PASS, SLOW],
   'harmony/regexp-property-lu-ui': [PASS, SLOW],
   'whitespaces': [PASS, SLOW],
   'generated-transition-stub': [PASS, SLOW],