Basic class members generation.

Split testData into 'classes' and 'expressions'.

compiler/testData/ir/irText/expressions/augmentedAssignment1.kt

@@ -0,0 +1,18 @@
+var p = 0
+
+fun testVariable() {
+    var x = 0
+    x += 1
+    x -= 2
+    x *= 3
+    x /= 4
+    x %= 5
+}
+
+fun testProperty() {
+    p += 1
+    p -= 2
+    p *= 3
+    p /= 4
+    p %= 5
+}