[atomicfu-K/N] Tests for K/N atomicfu-compiler-plugin

* `nativeTest` task now allows to provide compiler plugins that may be enabled during test compilation
* test sets for JVM and K/N backends are equal

KT-60800 describes all the issues with native tests that were solved in this commit.

Co-authored-by: Dmitriy Dolovov <Dmitriy.Dolovov@jetbrains.com>

Merge-request: KT-MR-11401
Merged-by: Maria Sokolova <maria.sokolova@jetbrains.com>

plugins/atomicfu/atomicfu-compiler/testData/nativeBox/atomics_basic/LockFreeLongCounterTest.kt

@@ -0,0 +1,61 @@
+import kotlinx.atomicfu.*
+import kotlin.test.*
+
+class LockFreeLongCounterTest {
+    private inline fun testWith(g: LockFreeLongCounter.() -> Long) {
+        val c = LockFreeLongCounter()
+        assertEquals(0L, c.g())
+        assertEquals(1L, c.increment())
+        assertEquals(1L, c.g())
+        assertEquals(2L, c.increment())
+        assertEquals(2L, c.g())
+    }
+
+    fun testBasic() = testWith { get() }
+
+    fun testGetInner() = testWith { getInner() }
+
+    fun testAdd2() {
+        val c = LockFreeLongCounter()
+        c.add2()
+        assertEquals(2L, c.get())
+        c.add2()
+        assertEquals(4L, c.get())
+    }
+
+    fun testSetM2() {
+        val c = LockFreeLongCounter()
+        c.setM2()
+        assertEquals(-2L, c.get())
+    }
+}
+
+class LockFreeLongCounter {
+    private val counter = atomic(0L)
+
+    fun get(): Long = counter.value
+
+    fun increment(): Long = counter.incrementAndGet()
+
+    fun add2() = counter.getAndAdd(2)
+
+    fun setM2() {
+        counter.value = -2L // LDC instruction here
+    }
+
+    fun getInner(): Long = Inner().getFromOuter()
+
+    // testing how an inner class can get access to it
+    private inner class Inner {
+        fun getFromOuter(): Long = counter.value
+    }
+}
+
+@Test
+fun box() {
+    val testClass = LockFreeLongCounterTest()
+    testClass.testBasic()
+    testClass.testAdd2()
+    testClass.testSetM2()
+    testClass.testGetInner()
+}