Never import object descriptors, for they may overwrite corresponding vals

compiler/testData/diagnostics/tests/scopes/ImportObjectAndUseAsSupertype.kt

@@ -0,0 +1,19 @@
+// FILE: a.kt
+
+package foo
+
+object Bar {
+    fun bar() {}
+}
+
+// FILE: b.kt
+
+package baz
+
+import foo.Bar
+
+class C: <!UNRESOLVED_REFERENCE!>Bar<!>
+
+fun test() {
+    Bar.bar()
+}