K2: do not build fake overrides for substituted package-private members

For example, `java.util.ArrayList.elementData` is a generic
package-private method. Not unwrapping intersection/substitution fake
overrides resulted in incorrect FQ names being compared in the package
visibility check, which led to the fake override always being created in
any subclass of ArrayList.

This change will help in testing IR fake overrides (KT-61360) because in
the current (temporary) mode, IrFakeOverrideRebuilder throws an
exception if initial fake overrides constructed by fir2ir differ from
the ones rebuilt by the IR -- and here they'll be different after fixing
KT-61366.

compiler/testData/ir/irText/firProblems/ArrayListOverrides.fir.ir.txt

@@ -6,11 +6,6 @@ FILE fqName:<root> fileName:/ArrayListOverrides.kt
         DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () declared in java.util.ArrayList'
           <E>: kotlin.String
         INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:A1 modality:FINAL visibility:public superTypes:[java.util.ArrayList<kotlin.String>]'
-    FUN FAKE_OVERRIDE name:elementData visibility:public/*package*/ modality:OPEN <> ($this:java.util.ArrayList<kotlin.String>, p0:kotlin.Int) returnType:@[FlexibleNullability] kotlin.String? [fake_override]
-      overridden:
-        public/*package*/ open fun elementData (p0: kotlin.Int): @[FlexibleNullability] E of java.util.ArrayList? declared in java.util.ArrayList
-      $this: VALUE_PARAMETER name:<this> type:java.util.ArrayList<kotlin.String>
-      VALUE_PARAMETER name:p0 index:0 type:kotlin.Int
     PROPERTY FAKE_OVERRIDE name:size visibility:public modality:OPEN [fake_override,val]
       overridden:
         public open size: kotlin.Int
@@ -208,11 +203,6 @@ FILE fqName:<root> fileName:/ArrayListOverrides.kt
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public open fun remove (x: kotlin.String): kotlin.Boolean declared in <root>.A2'
           CONST Boolean type=kotlin.Boolean value=true
-    FUN FAKE_OVERRIDE name:elementData visibility:public/*package*/ modality:OPEN <> ($this:java.util.ArrayList<kotlin.String>, p0:kotlin.Int) returnType:@[FlexibleNullability] kotlin.String? [fake_override]
-      overridden:
-        public/*package*/ open fun elementData (p0: kotlin.Int): @[FlexibleNullability] E of java.util.ArrayList? declared in java.util.ArrayList
-      $this: VALUE_PARAMETER name:<this> type:java.util.ArrayList<kotlin.String>
-      VALUE_PARAMETER name:p0 index:0 type:kotlin.Int
     PROPERTY FAKE_OVERRIDE name:size visibility:public modality:OPEN [fake_override,val]
       overridden:
         public open size: kotlin.Int