Update Gradle test version to 4.5.1, fix kapt1 multiversion and IC tests

that were not correctly tweaked for kapt1

libraries/tools/kotlin-gradle-plugin-integration-tests/build.gradle

@@ -132,7 +132,7 @@ task testsFromJps(type: Test) {
 }
 
 task testAdvanceGradleVersion(type: Test) {
-    def gradleVersionForTests = "4.3-rc-1"
+    def gradleVersionForTests = "4.5.1"
     systemProperty("kotlin.gradle.version.for.tests", gradleVersionForTests)
     dependsOn = test.dependsOn
     exclude jpsIncrementalTestsClass

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/KaptIncrementalIT.kt

@@ -29,16 +29,21 @@ abstract class KaptIncrementalBaseIT(val shouldUseStubs: Boolean, val useKapt3:
     protected open val projectName = "kaptIncrementalCompilationProject"
 
     private fun getProject() =
-            Project(projectName).apply {
-                setupWorkingDir()
-                val buildGradle = projectDir.parentFile.getFileByName("build.gradle")
-                buildGradle.modify { it.replace(GENERATE_STUBS_PLACEHOLDER, shouldUseStubs.toString()) }
+        Project(
+            projectName,
+            // When running with original kapt, use Gradle 3.5, because separate classes dirs (4.0+) are not supported
+            if (useKapt3) GradleVersionRequired.None else GradleVersionRequired.Exact("3.5")
+        ).apply {
+            setupWorkingDir()
+            val buildGradle = projectDir.parentFile.getFileByName("build.gradle")
+            buildGradle.modify { it.replace(GENERATE_STUBS_PLACEHOLDER, shouldUseStubs.toString()) }
 
-                if (useKapt3) {
-                    buildGradle.modify { it.replace(APPLY_KAPT3_PLUGIN_PLACEHOLDER, APPLY_KAPT3_PLUGIN) }
-                    allowOriginalKapt()
-                }
+            if (useKapt3) {
+                buildGradle.modify { it.replace(APPLY_KAPT3_PLUGIN_PLACEHOLDER, APPLY_KAPT3_PLUGIN) }
+            } else {
+                allowOriginalKapt()
             }
+        }
 
     private val annotatedElements =
             arrayOf("A", "funA", "valA", "funUtil", "valUtil", "B", "funB", "valB", "useB")

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/KotlinGradlePluginMultiVersionIT.kt

@@ -11,6 +11,7 @@ class KotlinGradlePluginMultiVersionIT : BaseMultiGradleVersionIT() {
     @Test
     fun testKaptProcessorPath() {
         val project = Project("kaptSimple", gradleVersion)
+        project.allowOriginalKapt()
 
         project.build("build") {
             assertSuccessful()

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/UpToDatenessIT.kt

@@ -122,7 +122,8 @@ class UpToDateIT : BaseGradleIT() {
         override fun mutateProject(project: Project) = with(project) {
             val kotlinOutputPath =
                 if (testGradleVersionAtLeast("4.0"))
-                    project.classesDir() else
+                    project.classesDir()
+                else
                     // Before 4.0, we should delete the classes from the temporary dir to make compileKotlin rerun:
                     "build/kotlin-classes/main/"