Mark asan/TestCases/zero_alloc.cpp unsupported on Mac for now

It's failing due to the malloc.h include, see comment on
#155943

Author: zmodem

compiler-rt/test/asan/TestCases/zero_alloc.cpp

@@ -1,5 +1,8 @@
 // RUN: %clang_asan -Wno-alloc-size -fsanitize-recover=address %s -o %t && %env_asan_opts=halt_on_error=0 %run %t 2>&1 | FileCheck %s
 
+// UNSUPPORTED: darwin
+// UNSUPPORTED: ios
+
 #include <malloc.h>
 #include <stdio.h>