gc.c: disable AddressSanitizer

* gc.c (mark_locations_array): disable AddressSanitizer.  based on a
  patch by halfie (Ruby Guy) at [ruby-core:57372].
  [ruby-core:56155] [Bug #8680]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43047 b2dd03c8-39d4-4d8f-98ff-823fe69b080e