Fix translation of interface with non-abstract methods in JS BE

Fix additional case of generic interfaces in KT-18187

compiler/testData/codegen/box/traits/interfaceWithNonAbstractFunIndirectGeneric.kt

@@ -0,0 +1,27 @@
+interface I<T> {
+    fun foo(x: T): String = "foo($x)"
+
+    fun bar(x: T, y: String = "default") = "bar($x,$y)"
+}
+
+interface J : I<String>
+
+class A : I<String>, J
+
+class B : J, I<String>
+
+fun box(): String {
+    val foo = A().foo("q")
+    if (foo != "foo(q)") return "fail1: $foo"
+
+    val bar1 = A().bar("w")
+    if (bar1 != "bar(w,default)") return "fail2: $bar1"
+
+    val bar2 = A().bar("e", "r")
+    if (bar2 != "bar(e,r)") return "fail3: $bar2"
+
+    val foo2 = B().foo("t")
+    if (foo2 != "foo(t)") return "fail4: $foo2"
+
+    return "OK"
+}