[Bug target/105162] [AArch64] outline-atomics drops dmb ish barrier on __sync builtins

[spop at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105162

--- Comment #2 from Sebastian Pop <spop at gcc dot gnu.org> ---
Created attachment 52750
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52750&action=edit
patch

Fix.