Add futex-line Awaitable atomic location abstraction

Author: polytypic

bench/bench_binaries.ml

@@ -25,6 +25,7 @@ let paths =
     lib "picos_mux.multififo";
     lib "picos_mux.random";
     lib "picos_mux.thread";
+    lib "picos_std.awaitable";
     lib "picos_std.event";
     lib "picos_std.finally";
     lib "picos_std.structured";

bench/dune

@@ -38,6 +38,7 @@
   picos_aux.mpscq
   picos_io
   picos_io.select
+  picos_std.awaitable
   picos_std.finally
   picos_std.structured
   picos_std.sync

lib/picos_std.awaitable/dune

@@ -0,0 +1,11 @@
+(library
+ (name picos_std_awaitable)
+ (public_name picos_std.awaitable)
+ (libraries picos picos_aux.htbl backoff multicore-magic))
+
+(mdx
+ (package picos_meta)
+ (enabled_if
+  (>= %{ocaml_version} 5.0.0))
+ (libraries picos picos_std.awaitable)
+ (files picos_std_awaitable.mli))