[Misc] Extract method in ExpectedActualDeclarationChecker for clarity

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt

@@ -79,10 +79,7 @@ class ExpectedActualDeclarationChecker(val argumentExtractors: List<ActualAnnota
 
         val shouldReportError =
             compatibility.allStrongIncompatibilities() ||
-                    Compatible !in compatibility && compatibility.values.flatMapTo(hashSetOf()) { it }.all { actual ->
+                    Compatible !in compatibility && descriptor.hasNoActualWithDiagnostic(compatibility)
-                val expectedOnes = ExpectedActualResolver.findExpectedForActual(actual, descriptor.module)
-                expectedOnes != null && Compatible in expectedOnes.keys
-            }
 
         if (shouldReportError) {
             assert(compatibility.keys.all { it is Incompatible })
@@ -99,6 +96,15 @@ class ExpectedActualDeclarationChecker(val argumentExtractors: List<ActualAnnota
         }
     }
 
+    private fun MemberDescriptor.hasNoActualWithDiagnostic(
+        compatibility: Map<Compatibility, List<MemberDescriptor>>
+    ): Boolean {
+        return compatibility.values.flatMapTo(hashSetOf()) { it }.all { actual ->
+            val expectedOnes = ExpectedActualResolver.findExpectedForActual(actual, module)
+            expectedOnes != null && Compatible in expectedOnes.keys
+        }
+    }
+
     private fun ExpectActualTracker.reportExpectActual(expected: MemberDescriptor, actualMembers: Sequence<MemberDescriptor>) {
         if (this is ExpectActualTracker.DoNothing) return