[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/atomic_extensions/LockFreeIntBitsTest.kt

@@ -0,0 +1,57 @@
+import kotlinx.atomicfu.*
+import kotlin.test.*
+
+class LockFreeIntBitsTest {
+    fun testBasic() {
+        val bs = LockFreeIntBits()
+        assertTrue(!bs[0])
+        assertTrue(bs.bitSet(0))
+        assertTrue(bs[0])
+        assertTrue(!bs.bitSet(0))
+
+        assertTrue(!bs[1])
+        assertTrue(bs.bitSet(1))
+        assertTrue(bs[1])
+        assertTrue(!bs.bitSet(1))
+        assertTrue(!bs.bitSet(0))
+
+        assertTrue(bs[0])
+        assertTrue(bs.bitClear(0))
+        assertTrue(!bs.bitClear(0))
+
+        assertTrue(bs[1])
+    }
+}
+
+class LockFreeIntBits {
+    private val bits = atomic(0)
+
+    private fun Int.mask() = 1 shl this
+
+    operator fun get(index: Int): Boolean = bits.value and index.mask() != 0
+
+    // User-defined private inline function
+    private inline fun bitUpdate(check: (Int) -> Boolean, upd: (Int) -> Int): Boolean {
+        bits.update {
+            if (check(it)) return false
+            upd(it)
+        }
+        return true
+    }
+
+    fun bitSet(index: Int): Boolean {
+        val mask = index.mask()
+        return bitUpdate({ it and mask != 0 }, { it or mask })
+    }
+
+    fun bitClear(index: Int): Boolean {
+        val mask = index.mask()
+        return bitUpdate({ it and mask == 0 }, { it and mask.inv() })
+    }
+}
+
+@Test
+fun box() {
+    val testClass = LockFreeIntBitsTest()
+    testClass.testBasic()
+}