[FIR] Discriminate abstract members when resolving on super

compiler/testData/diagnostics/tests/thisAndSuper/unqualifiedSuper/unqualifiedSuperWithAbstractMembers.fir.kt

@@ -22,7 +22,7 @@ interface I {
 
 class B : A(), I {
     override val x: Int = 12345
-    override val y: Int = super.<!AMBIGUITY!>y<!>
+    override val y: Int = super.y
 
     override fun foo(): Int {
         super.foo()
@@ -30,7 +30,7 @@ class B : A(), I {
     }
 
     override fun bar() {
-        super.<!AMBIGUITY!>bar<!>()
+        super.bar()
     }
 
     override fun qux() {

compiler/testData/diagnostics/tests/thisAndSuper/unqualifiedSuper/withMethodOverriddenInAnotherSupertype.fir.kt

@@ -15,7 +15,7 @@ class Test1 : C(), A {
         // Abstract 'foo' defined in 'C' wins against non-abstract 'foo' defined in 'A',
         // because 'C' is a subclass of 'A' (and 'C::foo' overrides 'A::foo'),
         // even though 'A' is explicitly listed in supertypes list for 'D'.
-        super.<!AMBIGUITY!>foo<!>()
+        super.foo()
     }
 }