Bug 1602845 - Enable 'return' UBSan check. r=froydnj

Differential Revision: https://phabricator.services.mozilla.com/D56626

--HG--
extra : moz-landing-system : lando

build/moz.configure/toolchain.configure

@@ -1471,6 +1471,7 @@ def ubsan(options):
         'integer-divide-by-zero',
         'object-size',
         'pointer-overflow',
+        'return',
         'vla-bound',
     ]