Replace map { ... }.filterNotNull() with mapNotNull { ... }

compiler/frontend.java/src/org/jetbrains/kotlin/inline/inlineUtil.kt

@@ -49,10 +49,10 @@ public fun inlineFunctionsJvmNames(bytes: ByteArray): Set<String> {
 private fun inlineFunctionsJvmNames(functions: List<ProtoBuf.Function>, nameResolver: NameResolver, protoTypeTable: ProtoBuf.TypeTable): Set<String> {
     val typeTable = TypeTable(protoTypeTable)
     val inlineFunctions = functions.filter { Flags.IS_INLINE.get(it.flags) }
-    val jvmNames = inlineFunctions.map {
+    val jvmNames = inlineFunctions.mapNotNull {
         JvmProtoBufUtil.getJvmMethodSignature(it, nameResolver, typeTable)
     }
-    return jvmNames.filterNotNull().toSet()
+    return jvmNames.toSet()
 }
 
 private fun readKotlinHeader(bytes: ByteArray): KotlinClassHeader {

compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/incremental/IncrementalPackageFragmentProvider.kt

@@ -119,10 +119,9 @@ public class IncrementalPackageFragmentProvider(
                         } ?: emptyList<String>()
 
                 val scopes = actualPackagePartFiles
-                        .map {
+                        .mapNotNull {
                             incrementalCache.getPackagePartData(it)
                         }
-                        .filterNotNull()
                         .map {
                             IncrementalPackageScope(JvmProtoBufUtil.readPackageDataFrom(it.data, it.strings))
                         }
@@ -149,7 +148,7 @@ public class IncrementalPackageFragmentProvider(
                 val partsNames: Collection<String>
         ) : PackageFragmentDescriptorImpl(moduleDescriptor, multifileClassFqName.parent()) {
             val memberScope = storageManager.createLazyValue {
-                val partsData = partsNames.map { incrementalCache.getPackagePartData(it) }.filterNotNull()
+                val partsData = partsNames.mapNotNull { incrementalCache.getPackagePartData(it) }
                 if (partsData.isEmpty())
                     MemberScope.Empty
                 else {
@@ -182,8 +181,7 @@ public class IncrementalPackageFragmentProvider(
 
                 if (LOG.isDebugEnabled) {
                     val allPackageParts = allMemberProtos
-                            .map(::getPackagePart)
-                            .filterNotNull()
+                            .mapNotNull(::getPackagePart)
                             .toSet()
                     val skippedPackageParts = allPackageParts.filter { shouldSkipPackagePart(it) }
 

compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/incremental/IncrementalPackagePartProvider.kt

@@ -38,7 +38,7 @@ internal class IncrementalPackagePartProvider private constructor(
         val packagePartsFromParent = parent.findPackageParts(packageFqName)
         if (packageFqName in fqNamesToIgnore) return packagePartsFromParent
 
-        val packagePartsFromCompiled = moduleMappings().map { it.findPackageParts(packageFqName) }.filterNotNull().flatMap { it.parts }
+        val packagePartsFromCompiled = moduleMappings().mapNotNull { it.findPackageParts(packageFqName) }.flatMap { it.parts }
         return (packagePartsFromCompiled + packagePartsFromParent).distinct()
     }
 

compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/SamAdapterFunctionsScope.kt

@@ -77,8 +77,7 @@ class SamAdapterFunctionsScope(storageManager: StorageManager) : BaseImportingSc
         return receiverTypes.flatMapTo(LinkedHashSet<FunctionDescriptor>()) { type ->
             type.memberScope.getContributedDescriptors(DescriptorKindFilter.FUNCTIONS)
                     .filterIsInstance<FunctionDescriptor>()
-                    .map { extensionForFunction(it.original) }
-                    .filterNotNull()
+                    .mapNotNull { extensionForFunction(it.original) }
         }
     }