kotlinx.atomicfu compiler plugin for JS_IR backend (#4581)

* kotlinx.atomicfu compiler plugin for JS_IR

Support transformations of atomic operations introduced by the kotlinx.atomicfu library for the JS_IR backend. Compiler plugin is applied externally by the kotlinx.atomicfu gradle plugin.

* Apply compiler plugin for JS platform only

* New plugin test structure

* testGroupOutputDirPrefix changed

plugins/atomicfu/atomicfu-compiler/testData/box/ScopeTest.kt

@@ -0,0 +1,45 @@
+import kotlinx.atomicfu.*
+import kotlin.test.*
+
+class AA(val value: Int) {
+    val b = B(value + 1)
+    val c = C(D(E(value + 1)))
+
+    fun updateToB(affected: Any): Boolean {
+        (affected as AtomicState).state.compareAndSet(this, b)
+        return (affected.state.value is B && (affected.state.value as B).value == value + 1)
+    }
+
+    fun manyProperties(affected: Any): Boolean {
+        (affected as AtomicState).state.compareAndSet(this, c.d.e)
+        return (affected.state.value is E && (affected.state.value as E).x == value + 1)
+    }
+}
+
+class B (val value: Int)
+
+class C (val d: D)
+class D (val e: E)
+class E (val x: Int)
+
+
+class AtomicState(value: Any) {
+    val state = atomic<Any?>(value)
+}
+
+class ScopeTest {
+    fun scopeTest() {
+        val a = AA(0)
+        val affected: Any = AtomicState(a)
+        check(a.updateToB(affected))
+        val a1 = AA(0)
+        val affected1: Any = AtomicState(a1)
+        check(a1.manyProperties(affected1))
+    }
+}
+
+fun box(): String {
+    val testClass = ScopeTest()
+    testClass.scopeTest()
+    return "OK"
+}