Refine 'isMoreSpecific' calculation

Choose member with better visibility, it's needed for proper calculation
of types intersection member scope

 #KT-10481 Fixed

compiler/testData/diagnostics/tests/smartCasts/intersectionScope/moreSpecificVisibility.kt

@@ -0,0 +1,16 @@
+abstract class A {
+    abstract protected fun foo(): String
+    abstract protected val bar: String
+}
+
+interface B {
+    fun foo(): String
+    val bar: String
+}
+
+fun test(x: A) {
+    if (x is B) {
+        <!DEBUG_INFO_SMARTCAST!>x<!>.foo()
+        <!DEBUG_INFO_SMARTCAST!>x<!>.bar
+    }
+}