[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/dataFlowInfoTraversal/ArrayAccess.fir.kt

@@ -0,0 +1,13 @@
+fun bar(x: Int): Int = x + 1
+
+fun foo() {
+    val x: Int? = null
+    val a = Array<Int>(3, {0})
+
+    if (x != null) bar(a[x]) else bar(a[x])
+    bar(a[if (x == null) 0 else x])
+    bar(a[x])
+    
+    "123"[x];
+    if (x != null) "123"[x];
+}