Report conflicting signatures that are purely inherited from traits

When all signatures are inherited from traits, the origin elements lie outside of the class in question

compiler/testData/diagnostics/tests/duplicateJvmSignature/erasure/twoTraitsAndOwnFunction.kt

@@ -0,0 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+trait Foo<T> {
+    fun foo(l: List<T>) {}
+}
+
+trait Bar<T> {
+    fun foo(l: List<T>) {}
+}
+
+class Baz(): Foo<String>, Bar<Int> {
+    <!CONFLICTING_JVM_DECLARATIONS!>fun foo(l: List<Long>)<!> {}
+}