[FIR-TEST] Move analysis tests to separate module

compiler/fir/analysis-tests/testData/resolveWithStdlib/arrayFirstOrNull.kt

@@ -0,0 +1,11 @@
+interface G {
+    val a: Array<out G>
+}
+
+fun goo(g: G) {
+    val x = g.a.firstOrNullX()
+}
+
+public fun <T> Array<out T>.firstOrNullX(): T? {
+    return if (isEmpty()) null else this[0]
+}