Basic class members generation.

Split testData into 'classes' and 'expressions'.

compiler/testData/ir/irText/expressions/arrayAugmentedAssignment1.kt

@@ -0,0 +1,17 @@
+fun foo(): IntArray = intArrayOf(1, 2, 3)
+fun bar() = 42
+
+class C(val x: IntArray)
+
+fun testVariable() {
+    var x = foo()
+    x[0] += 1
+}
+
+fun testCall() {
+    foo()[bar()] *= 2
+}
+
+fun testMember(c: C) {
+    c.x[0]++
+}