Fix for a bug that caused invalid code generated for calling extension from another extension.

js/js.translator/testFiles/extensionFunction/cases/extensionForSuperclass.kt

@@ -0,0 +1,17 @@
+package foo
+
+open class A() {
+    open fun c() = 2
+}
+
+class B(): A() {
+    override fun c() = 3
+}
+
+fun B.t() = d() + 1
+
+fun A.d() = c() + 3
+
+fun box() : Boolean {
+    return A().d() == 5 && B().d() == 6 && B().t() == 7
+}

js/js.translator/testFiles/extensionFunction/cases/implicitReceiverInExtension.kt

@@ -0,0 +1,7 @@
+package foo
+
+fun <T> T.toPrefixedString(prefix: String = "", suffix: String="") = prefix + toString() + suffix
+
+fun box() : Boolean {
+    return ("mama".toPrefixedString(suffix="321", prefix="papa") == "papamama321")
+}

js/js.translator/testFiles/extensionFunction/cases/superClassMemberInExtension.kt

@@ -0,0 +1,14 @@
+package foo
+
+open class A() {
+    open fun c() = 2
+}
+
+class B(): A() {
+}
+
+fun B.d() = c() + 3
+
+fun box() : Boolean {
+    return B().d() == 5
+}