[lldb/testsuite] XFail TestBuiltinTrap.py not only on linux

Summary:
TestBuiltinTrap fail on darwin embedded because the `__builin_trap`
builtin doesn't get any line info attached to it by clang when
building for arm64.

The test was already XFailed for linux arm(64), I presume for the same
reasons. This patch just XFails it independently of the platform.

Reviewers: labath

Subscribers: kristof.beyls, danielkiss, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D76408