Minor: remove warnings

compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateSignatureDiagnostics.kt

@@ -26,12 +26,9 @@ import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor.Kind.DELEGATION
 import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor.Kind.FAKE_OVERRIDE
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.fileClasses.JvmFileClassesProvider
-import org.jetbrains.kotlin.fileClasses.isInsideJvmMultifileClassFile
-import org.jetbrains.kotlin.idea.MainFunctionDetector
 import org.jetbrains.kotlin.load.java.descriptors.SamAdapterDescriptor
 import org.jetbrains.kotlin.load.java.descriptors.getParentJavaStaticClassScope
 import org.jetbrains.kotlin.load.kotlin.incremental.components.IncrementalCache
-import org.jetbrains.kotlin.psi.KtNamedFunction
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.*
@@ -57,8 +54,6 @@ class BuilderFactoryForDuplicateSignatureDiagnostics(
     // Avoid errors when some classes are not loaded for some reason
     private val typeMapper = JetTypeMapper(bindingContext, ClassBuilderMode.LIGHT_CLASSES, fileClassesProvider, incrementalCache, moduleName)
 
-    private val mainFunctionDetector = MainFunctionDetector(bindingContext)
-
     override fun handleClashingSignatures(data: ConflictingJvmDeclarationsData) {
         val noOwnImplementations = data.signatureOrigins.all { it.originKind in EXTERNAL_SOURCES_KINDS }
 
@@ -102,7 +97,7 @@ class BuilderFactoryForDuplicateSignatureDiagnostics(
 
         signatures@
         for ((rawSignature, origins) in groupedBySignature.entrySet()) {
-            if (origins.size() <= 1) continue
+            if (origins.size <= 1) continue
 
             var memberElement: PsiElement? = null
             var ownNonFakeCount = 0