FreeBSD: ASAN hang on aarch64

ASAN hangs on aarch64 FreeBSD. Disabling until we have a chance to dig
through it.

Author: etcwilde

test/Sanitizers/asan/asan.swift

@@ -1,5 +1,10 @@
 // XFAIL: OS=windows-msvc
 
+// This test hangs on aarch64 FreeBSD
+// XFAIL will try to run the test and the verify that the test fails, which
+// still hits the hang.
+// UNSUPPORTED: OS=freebsd && CPU=aarch64
+
 // RUN: %target-swiftc_driver %s -g -sanitize=address -o %t_asan-binary
 // RUN: %target-codesign %t_asan-binary
 // RUN: env %env-ASAN_OPTIONS=abort_on_error=0 not %target-run %t_asan-binary 2>&1 | %FileCheck %s