Multi-decl for loops fixed

compiler/testData/codegen/multiDecl/MultiDeclForComponentExtensions.kt

@@ -0,0 +1,22 @@
+class C(val i: Int) {
+}
+
+fun C.component1() = i + 1
+fun C.component2() = i + 2
+
+fun doTest(l : java.util.ArrayList<C>): String {
+    var s = ""
+    for ((a, b) in l) {
+      s += "$a:$b;"
+    }
+    return s
+}
+
+fun box(): String {
+  val l = java.util.ArrayList<C>()
+  l.add(C(0))
+  l.add(C(1))
+  l.add(C(2))
+  val s = doTest(l)
+  return if (s == "1:2;2:3;3:4;") "OK" else "fail: $s"
+}