[sanitizer] Handle malloc_destroy_zone() on Darwin

We currently have a interceptor for malloc_create_zone, which returns a new zone that redirects all the zone requests to our sanitizer zone. However, calling malloc_destroy_zone on that zone will cause libmalloc to print out some warning messages, because the zone is not registered in the list of zones. This patch handles this and adds a testcase for that.

Differential Revision: https://reviews.llvm.org/D27083

llvm-svn: 289375