Do not report "can be private" on expect or actual declarations

So #KT-24374 Fixed
So #KT-24537 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/MemberVisibilityCanBePrivateInspection.kt

@@ -39,12 +39,11 @@ import org.jetbrains.kotlin.idea.refactoring.isConstructorDeclaredProperty
 import org.jetbrains.kotlin.idea.search.isCheapEnoughToSearchConsideringOperators
 import org.jetbrains.kotlin.idea.search.usagesSearch.dataClassComponentFunction
 import org.jetbrains.kotlin.idea.stubindex.KotlinSourceFilterScope
+import org.jetbrains.kotlin.idea.util.isEffectivelyActual
+import org.jetbrains.kotlin.idea.util.isExpectDeclaration
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
-import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
-import org.jetbrains.kotlin.psi.psiUtil.isPrivate
-import org.jetbrains.kotlin.psi.psiUtil.visibilityModifier
+import org.jetbrains.kotlin.psi.psiUtil.*
 import org.jetbrains.kotlin.resolve.jvm.annotations.hasJvmFieldAnnotation
 
 class MemberVisibilityCanBePrivateInspection : AbstractKotlinInspection() {
@@ -76,6 +75,7 @@ class MemberVisibilityCanBePrivateInspection : AbstractKotlinInspection() {
 
     private fun canBePrivate(declaration: KtNamedDeclaration): Boolean {
         if (declaration.hasModifier(KtTokens.PRIVATE_KEYWORD) || declaration.hasModifier(KtTokens.OVERRIDE_KEYWORD)) return false
+        if (declaration.hasActualModifier() || declaration.isExpectDeclaration()) return false
 
         val descriptor = (declaration.toDescriptor() as? DeclarationDescriptorWithVisibility) ?: return false
         when (descriptor.effectiveVisibility()) {

idea/testData/inspections/memberVisibilityCanBePrivate/test.kt

@@ -209,3 +209,13 @@ fun withLocal(): Int {
 class Math {
     @test.anno.EntryPoint fun fact(n: Int) = if (n < 2) 1 else n * fact(n - 1)
 }
+
+expect class Expect {
+    fun foo()
+    val bar: Int
+}
+
+actual class Actual {
+    actual fun foo() {}
+    actual val bar = 42
+}