[JS BE] Fix the crash on compound operations with a qualified call on left side

#KT-22001 Fixed

compiler/testData/codegen/box/objects/compoundAssignmentToPropertyWithQualifier.kt

@@ -0,0 +1,48 @@
+var log = ""
+
+class A(p: String) {
+    var pp = p
+
+    init {
+        log += "init($p);"
+    }
+}
+
+operator fun A.plusAssign(s: String) {
+    pp += s
+    log += "pp = $pp;"
+}
+
+class D {
+    val a = A("D")
+}
+
+object E {
+    val t = A("E")
+}
+
+fun box(): String {
+    log = ""
+    val d = D()
+    d.a += "foo"
+
+    if (log != "init(D);pp = Dfoo;") return "1: log = \"$log\""
+
+    log = ""
+    E.t += "ET"
+
+    if (log != "init(E);pp = EET;") return "2: log = \"$log\""
+
+    log = ""
+    val c = object { val b = object { val a = A("xcv") } }
+    c.b.a += "eee"
+
+    if (log != "init(xcv);pp = xcveee;") return "3: log = \"$log\""
+
+    val b = object { val a = A("qwe") }
+    b.a.pp += "ui"
+
+    if (b.a.pp != "qweui") return "4: b.a.pp = \"${b.a.pp}\""
+
+    return "OK"
+}