[foozzie] Add slow-path correctness fuzzing variants

TBR=jgruber@chromium.org
NOTRY=true

Bug: v8:7120
Change-Id: Ib8375e6ad811d9299c9a477ed39c6bc76c0c90dd
Reviewed-on: https://chromium-review.googlesource.com/852232
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50382}

tools/foozzie/v8_foozzie.py

@@ -55,6 +55,15 @@ CONFIGS = dict(
     '--no-lazy-inner-functions',
     '--suppress-asm-messages',
   ],
+  slow_path=[
+    '--force-slow-path',
+    '--suppress-asm-messages',
+  ],
+  slow_path_opt=[
+    '--always-opt',
+    '--force-slow-path',
+    '--suppress-asm-messages',
+  ],
   trusted=[
     '--no-untrusted-code-mitigations',
     '--suppress-asm-messages',