Drop forcing Java task to recompile

We don't support Gradle <= 3.5 at the moment,
it does not make sense to have the code for Gradle < 2.14

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPlugin.kt

@@ -590,20 +590,6 @@ abstract class AbstractAndroidProjectHandler<V>(private val kotlinConfigurationT
 internal fun configureJavaTask(kotlinTask: KotlinCompile, javaTask: AbstractCompile, logger: Logger) {
     kotlinTask.javaOutputDir = javaTask.destinationDir
 
-    // Gradle Java IC in older Gradle versions (before 2.14) cannot check .class directories updates.
-    // To make it work, reset the up-to-date status of compileJava with this flag.
-    kotlinTask.anyClassesCompiled = false
-    val gradleSupportsJavaIcWithClassesDirs = ParsedGradleVersion.parse(javaTask.project.gradle.gradleVersion)
-                                                      ?.let { it >= ParsedGradleVersion(2, 14) } ?: false
-    if (!gradleSupportsJavaIcWithClassesDirs) {
-        javaTask.outputs.upToDateWhen { task ->
-            if (kotlinTask.anyClassesCompiled) {
-                logger.info("Marking $task out of date, because kotlin classes are changed")
-                false
-            } else true
-        }
-    }
-
     // Make Gradle check if the javaTask is up-to-date based on the Kotlin classes
     javaTask.inputsCompatible.run {
         if (isBuildCacheSupported()) {

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/Tasks.kt

@@ -180,10 +180,6 @@ abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractKo
                 ?: coroutinesFromGradleProperties
                 ?: Coroutines.DEFAULT
 
-    // TODO: consider more reliable approach (see usage)
-    @get:Internal
-    internal var anyClassesCompiled: Boolean = false
-
     @get:Internal
     internal var friendTaskName: String? = null
 
@@ -401,7 +397,6 @@ open class KotlinCompile : AbstractKotlinCompile<K2JVMCompilerArguments>(), Kotl
             cleanupOnError()
             throw e
         }
-        anyClassesCompiled = true
     }
 
     private fun disableMultiModuleICIfNeeded() {