Upgrade toolchain to api/lv 1.4

compiler/cli/build.gradle.kts

@@ -57,8 +57,8 @@ sourceSets {
 
 tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>> {
     kotlinOptions {
-        languageVersion = "1.3"
-        apiVersion = "1.3"
+        languageVersion = "1.4"
+        apiVersion = "1.4"
         freeCompilerArgs = freeCompilerArgs - "-progressive" + listOf(
             "-Xskip-prerelease-check", "-Xsuppress-version-warnings", "-Xuse-mixed-named-arguments", "-Xnew-inference"
         )

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/JvmRuntimeVersionsConsistencyChecker.kt

@@ -233,8 +233,8 @@ object JvmRuntimeVersionsConsistencyChecker {
         jars: List<KotlinLibraryFile>
     ): MavenComparableVersion? {
         assert(jars.isNotEmpty()) { "'jars' must not be empty" }
-        val oldestVersion = jars.minBy { it.version }!!.version
-        val newestVersion = jars.maxBy { it.version }!!.version
+        val oldestVersion = jars.minOf { it.version }
+        val newestVersion = jars.maxOf { it.version }
 
         // If the oldest version is the same as the newest version, then all jars have the same version
         if (oldestVersion == newestVersion) return oldestVersion
@@ -250,9 +250,9 @@ object JvmRuntimeVersionsConsistencyChecker {
         // we suggest to provide an explicit dependency on version X.
         // TODO: report this depending on the content of the jars instead
         val minReflectJar =
-            jars.filter { it.file.name.startsWith("kotlin-reflect") }.minBy { it.version }
+            jars.filter { it.file.name.startsWith("kotlin-reflect") }.minByOrNull { it.version }
         val maxStdlibJar =
-            jars.filter { it.file.name.startsWith("kotlin-runtime") || it.file.name.startsWith("kotlin-stdlib") }.maxBy { it.version }
+            jars.filter { it.file.name.startsWith("kotlin-runtime") || it.file.name.startsWith("kotlin-stdlib") }.maxByOrNull { it.version }
         if (minReflectJar != null && maxStdlibJar != null && minReflectJar.version < maxStdlibJar.version) {
             messageCollector.issue(
                 null,