std.concurrency.initOnce does not work with -preview=nosharedaccess

[dlangBugzillaToGithub]

sludwig (@s-ludwig) reported this on 2024-11-07T10:51:58Z

Transfered from https://issues.dlang.org/show_bug.cgi?id=24847

Description

---
import std.concurrency;
class C {}
shared C instance;
void main()
{
	auto obj = initOnce!instance(new C);
}
---

When compiling with DMD 2.109.1 and `-preview=nosharedaccess`, results in:

/dlang/dmd/linux/bin64/../../src/phobos/std/concurrency.d(2751): Error: direct access to shared `mutex` is not allowed, see `core.atomic`
/dlang/dmd/linux/bin64/../../src/phobos/std/concurrency.d(2755): Error: direct access to shared `instance` is not allowed, see `core.atomic`
/dlang/dmd/linux/bin64/../../src/phobos/std/concurrency.d(2684): Error: template instance `std.concurrency.initOnce!(instance)` error instantiating
onlineapp.d(6):        instantiated from here: `initOnce!(instance)`