KT-2752: remove diagnostic that reports about overridden method having several names from different sources. Generate proxies instead. Fix reporting name clash when two distinct fake overrides require same name.

compiler/testData/codegen/box/bridges/jsNative.kt

@@ -13,6 +13,12 @@ class C : A, B {
     override fun foo(value: Int) = "C.foo($value)"
 }
 
+open class D {
+    open fun foo(value: Int) = "D.foo($value)"
+}
+
+class E : D(), A, B
+
 fun box(): String {
     val a: A = C()
     assertEquals("C.foo(55)", a.foo(55))
@@ -24,5 +30,15 @@ fun box(): String {
     assertEquals("C.foo(42)", d.foo(42))
     assertEquals("C.foo(99)", d.`foo_za3lpa$`(99))
 
+    val da: A = E()
+    assertEquals("D.foo(55)", da.foo(55))
+
+    val db: B = E()
+    assertEquals("D.foo(23)", db.foo(23))
+
+    val dd: dynamic = E()
+    assertEquals("D.foo(42)", dd.foo(42))
+    assertEquals("D.foo(99)", dd.`foo_za3lpa$`(99))
+
     return "OK"
 }