Mark the _state field as atomic and move to proper atomics instead of llvmcall

[gbaraldi]

No description provided.

[giordano]

https://buildkite.com/julialang/julia-master/builds/39245#019157be-da72-4fb0-9294-7835a6bdcbff/830-1686

Error in testset Serialization:
Error During Test at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-master/julia-3eb9ab3e1c/share/julia/test/testdefs.jl:24
  Got exception outside of a @test
  LoadError: ConcurrencyViolationError("setfield!: atomic field cannot be written non-atomically")
  Stacktrace:
    [1] setproperty!
      @ ./Base.jl:53 [inlined]
    [2] setproperty!
      @ ./task.jl:193 [inlined]
    [3] deserialize(s::Serializer{IOBuffer}, ::Type{Task})
      @ Serialization /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-master/julia-3eb9ab3e1c/share/julia/stdlib/v1.12/Serialization/src/Serialization.jl:1575

looks relevant

[vchuravy]

Fixes #55125 (comment)

See #55125 in general for which tests to update. I think you need to simply adjust the serialization code to also use an atomic here.

[gbaraldi]

Looking at the uses of _state most are unordered atomics so I won't change them. But they might deserve a look

[giordano]

I presume this is good to go?