Coroutines debugger may overwrite the actual state of coroutine during asynchronous resume

[qwwdfsad]

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Consider the following situation when the dispatcher in the context is multithreaded

suspend fun foo() = yield()

It basically can be boiled down to the following pseudocode:

fun foo(...) {
    uCont.intercepted().dispatchUsingDispatcher()
    // Notify the debugger the coroutine is suspended 
    probeCoroutineSuspended()
    return COROUTINE_SUSPENDED // Unroll the stack
}

where dispatch concurrently invokes probeCoroutineResumed to notify the debugger the coroutine is actually executing right now.

The problem is straightforward -- if timings are unlucky enough, probeCoroutineResumed can be invoked before probeCoroutineSuspended, with probeCoroutineSuspended overwriting the state and leaving it as SUSPENDED

[qwwdfsad]

Steps to reproduce:

• add while (true) to RunningThreadStackMergeTest
• Re-run it once every 5 secs, the bug reproducer only before C2 JIT kicks in

Failing build https://teamcity.jetbrains.com/buildConfiguration/KotlinTools_KotlinxCoroutines_Build/3793970?showRootCauses=false&expandBuildChangesSection=true&expandBuildProblemsSection=true&expandBuildTestsSection=true