[RFC] libstdc++ atomicity, x86 agnostic version

[Gabriel Dos Reis]

Benjamin Kosnik <bkoz@redhat.com> writes:

| One way around this would be to make these atomic functions gcc
| builtins.

This is  what I vote for.

|  These would be different semantics than other gcc builtins,
| however, because there could be no fall back to a support library in the
| case of failure to use the builtin.

We already have built-ins that ought to be expanded by GCC.

-- Gaby