Move callable reference diagnostic tests to non-stdlib

compiler/testData/diagnostics/tests/callableReference/function/noAmbiguityMemberVsTopLevel.kt

@@ -0,0 +1,15 @@
+// !CHECK_TYPE
+
+import kotlin.reflect.KMemberFunction0
+
+fun foo() {}
+
+class A {
+    fun foo() {}
+    
+    fun main() {
+        val x = ::foo
+
+        checkSubtype<KMemberFunction0<A, Unit>>(x)
+    }
+}