Three small MSVC-only build fixes that travel together:
* compat/msvc/stdatomic.h: define atomic_uint_fast64_t. It is used by
rist-private.h for the sender/receiver data_fd rx/tx packet and byte
counters. Without this the MSVC fallback path fails to compile as
soon as any caller reaches those members.
* compat/msvc/stdatomic.h: fix a one-underscore typo on the
atomic_uint_fast16_t typedef (_declspec -> __declspec). MSVC accepts
the single-underscore spelling as a deprecated alias and newer
releases warn on it.
* meson.build: when the compiler is MSVC, enable /std:c11 (or /std:c17
as a fallback) so MSVC's own <stdatomic.h> becomes visible; propagate
stdatomic_dependency through the exported librist_dep so consumers
linking against librist get the same atomics plumbing.
Together with the preceding poll_win fix this is what Manuel's AI-
generated patch was trying to achieve; this version keeps the real
fixes, drops the churn, and makes the commit shape readable.
Reported-by: Manuel <manueldev@code.videolan.org>
Refs: https://code.videolan.org/rist/librist/-/issues/182
Sergio Ammirata
49ec8c6698